Patent Publication Number: US-9419227-B2

Title: Spirally configured cis-stilbene/fluorene hybrid materials as hole-blocking type electron-transporters for OLED

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. Ser. No. 14/583,619, filed Dec. 27, 2014, which claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 103135653, filed in Taiwan, Republic of China on Oct. 15, 2014, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the technology field of carrier transport materials, and more particularly to a spirally configured cis-stilbene/fluorene hybrid material as a hole-blocking type electron-transporters for OLEDs. 
     2. Description of the Prior Art 
     It is well known that organic light emitting diode (OLED) was initially invented and proposed by Eastman Kodak Company through a vacuum evaporation method. Tang and VanSlyke of Kodak Company deposited an electron transport material such as Alq 3  on a transparent indium tin oxide (abbreviated as ITO) glass formed with an organic layer of aromatic diamine thereon, and subsequently completed the fabrication of an organic electroluminescent (EL) device after a metal electrode is vapor-deposited onto the Alq 3  layer. The organic EL device currently becomes a new generation lighting device or display because of high brightness, fast response speed, light weight, compactness, true color, no difference in viewing angles, without using any LCD backlight plates, and low power consumption. 
     Recently, some interlayers such as electron transport layer and hole transport layer are added between the cathode and the anode for increasing the current efficiency and power efficiency of the OLEDs. For example, an organic light emitting diode (OLED)  1 ′ shown in the FIGURE is designed to consist of: a cathode  11 ′, an electron injection layer  13 ′, a light emitting layer  14 ′, a hole transport layer  16 ′, and an anode  18 ′. 
     In device function concept, the light emitted by the OLED  1 ′ is resulted from excitons produced by the recombination of electrons and holes in the light emitting layer  14 ′. However, according to theoretical speculation, the ratio of the excitons with singlet excited state and the excitons with triplet excited state is 3:1. So that, when a small molecular fluorescent material is used as the light-emitting layer  14 ′ of the OLED  1 ′, there are about 25% excitons being used in emitting light, and the rest of 75% excitons with triplet excited state are lost through non-luminescence mechanism. For this reason, the general fluorescent material performs a maximum quantum yield of 25% in limit which amounts to an external quantum efficiency of 5% in the device. 
     Moreover, researches further find that certain hole transport material can simultaneously perform electron confining ability, such as the material represented by following chemical formulas 1′ and 2′. The chemical formula 1′ represents the chemical structure of Tris(4-carbazoyl-9-ylphenyl)amine, which is called TCTA in abbreviation. The chemical formula 2′ represents the chemical structure of N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine called NPB in abbreviation. 
     
       
         
         
             
             
         
       
     
     Recently, for effectively increasing the lighting performance of OLEDs, OLED manufactures and researchers have made great efforts to develop electron transport materials with hole blocking functionality, such as TmPyPb, TPBi, 3TPYMB, BmPyPb, and DPyPA represented by following chemical formula 3′-7′, respectively. Wherein TmPyPb is the abbreviation of 3,3′-[5′-[3-(3-Pyridinyl)phenyl][1,1′:3′,1″-terphenyl]-3,3″-diyl]bispyridine, TPBi is the abbreviation of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 3TPYMB is the abbreviation of Tris(2,4,6-triMethyl-3-(pyridin-3-yl)phenyl)borane, BmPyPb is the abbreviation of 1,3-bis(3,5-dipyrid-3-yl-phenyl)benzene, and DPyPA is the abbreviation of 9,10-bis(3-(pyridin-3-yl)phenyl)anthracene. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In spite of various electron transport materials with hole blocking functionality have been developed, the phosphorescence OLEDs applied with the said electron transport materials still cannot perform outstanding luminous efficiency and device lifetime. Accordingly, in view of the conventional or commercial electron transport materials with hole blocking functionality still including drawbacks, the inventor of the present application has made great efforts to make inventive research thereon and eventually provided a spirally configured cis-stilbene/fluorene hybrid material as hole-blocking type electron-transporter for OLED. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a spirally configured cis-stilbene/fluorene hybrid materials, which are spirally-configured cis-stilbene/fluorene derivatives having glass transition temperatures ranged from 110° C. to 135° C., decomposition temperatures ranged from 380° C. to 425° C., reversible electron transport property, and balanced charges motilities. In addition, a variety of experimental data have proved that this spirally configured cis-stilbene/fluorene hybrid materials can indeed be used as hole-blocking type electron-transporters and/or n-type host materials for OLEDs; moreover, the experimental data also reveal that the OLEDs using the spirally configured cis-stilbene/fluorene hybrid materials can indeed be used as the hole-blocking type electron-transporters and are able to show excellent external quantum efficiency (η ext ), current efficiency (η c ), power efficiency (η p ), maximum luminance (L max ), and device lifetime better than those of phosphorescent OLEDs based on the conventional or commercial electron transport materials. 
     Accordingly, in order to achieve the primary objective of the present invention, the inventor of the present invention provides a series of spirally configured cis-stilbene/fluorene hybrid materials for OLEDs, wherein the spirally configured cis-stilbene/fluorene hybrid materials are spirally-configured cis-stilbene/fluorene derivatives having the functions to block holes and constructed by at least one cis-Stilbene based component and at least one fluorene based component; moreover, the spirally configured cis-stilbene/fluorene hybrid materials can also applied to light-emitting host materials. 
     According to one embodiment of the spirally configured cis-stilbene/fluorene hybrid materials, wherein the said spirally-configured cis-stilbene/fluorene derivatives are represented by following chemical formula I: 
     
       
         
         
             
             
         
       
     
     In the chemical formula I, R1-R2 are selected from the groups consisting of following chemical formula I-1, chemical formula I-2, chemical formula I-3, chemical formula I-4, chemical formula I-5a, chemical formula I-5b, chemical formula I-5c, chemical formula I-6a, chemical formula I-6b, and chemical formula I-6c: 
     
       
         
         
             
             
         
       
     
     Wherein X in aforesaid chemical formula I-5a, chemical formula I-5b, chemical formula I-6a, and chemical formula I-6b is C—H group or N group, and R3 is selected from the group consisting of following chemical formula I-7 and chemical formula I-8: 
     
       
         
         
             
             
         
       
     
     According to one embodiment of the spirally configured cis-stilbene/fluorene hybrid materials, wherein the spirally configured cis-stilbene/fluorene hybrid materials are represented by formula II, chemical formula III, chemical formula IV, chemical formula V, chemical formula VIa, chemical formula VIb, chemical formula VIc, chemical formula VIIa, chemical formula VIIb, and chemical formula VIIc: 
     
       
         
         
             
             
         
       
     
     wherein R is hydrogen group or tert-butyl group, and X is C—H or N group. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention as well as a preferred mode of use and advantages thereof will be best understood by referring to the following detailed description of an illustrative embodiment in conjunction with the accompanying drawings, wherein: 
       The FIGURE is a framework view of a conventional organic light emitting diode (OLED). 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     To more clearly describe spirally configured cis-stilbene/fluorene hybrid materials for OLEDs according to the present invention, embodiments of the present invention will be described in detail with reference to the attached drawings hereinafter. 
     The present invention provides a series of spirally configured cis-stilbene/fluorene hybrid materials for OLEDs. OLED comprises a bottom electrode, at least one interlayer and a top electrode sequentially disposed on a substrate, and the spirally configured cis-stilbene/fluorene hybrid materials are applied in the interlayer. The spirally configured cis-stilbene/fluorene hybrid materials, constructed by at least one cis-Stilbene based component and at least one fluorene based component, are spirally-configured cis-stilbene/fluorene derivatives having the functions to block holes. These spirally configured cis-stilbene/fluorene hybrid materials are mainly applied in OLEDs for being as an electron transport layer and/or a hole blocking layer; moreover, these spirally configured cis-stilbene/fluorene hybrid materials can also be applied in a solar cell for being as a carrier transport layer. 
     In the present invention, the said spirally-configured cis-stilbene/fluorene derivatives are represented by following chemical formula I: 
     
       
         
         
             
             
         
       
     
     In the chemical formula I, R1-R2 is selected from the group consisting of following chemical formula I-1, chemical formula I-2, chemical formula I-3, chemical formula I-4, chemical formula I-5a, chemical formula I-5b, chemical formula I-5c, chemical formula I-6a, chemical formula I-6b, and chemical formula I-6c: 
     
       
         
         
             
             
         
       
     
     In the chemical formulas, X in aforesaid chemical formula I-5a, chemical formula I-5b, chemical formula I-6a, and chemical formula I-6b is C—H group or N group, and R3 is selected from the group consisting of following chemical formula I-7 and chemical formula I-8: 
     
       
         
         
             
             
         
       
     
     To manufacture the said spirally configured cis-stilbene/fluorene hybrid materials of the present invention, a key intermediate product needs to be firstly fabricated by using following steps:
     (1) dissolving 30 mM 2-bromobiphenyl of 5.2 mL in 100 mL of anhydrous tetrahydrofuran (THF);   (2) placing the solution obtained from the step (1) in an environment of −78° C. for standing;   (3) taking 12 mL of n-butyllithium in hexanes solution (30 mM) from a n-butyllithium solution 2.5 M in hexanes, and then adding the 12 mL n-butyllithium hexanes solution dropwise into the solution obtained from the step (2) and stirring for 30 min   (4) dissolving 20 mM 3,7-dibromo-dibenzosuberenone of 7.28 g in 60 mL of anhydrous THF;   (5) adding the solution obtained from step (4) to the reaction mixture in step (3) dropwise;   (6) adding 10 mL of saturated aqueous sodium bicarbonate solution into the product obtained from the step (5) for executing a quenching reaction, and then remove the THF by rotary evaporation;   (7) treating the product obtained from the step (6) with a extracting process by using dichloromethane, and then obtaining an extract liquid extract;   (8) adding 5 g magnesium sulfate into the extract liquid extract, and then treat a drying process and a filtering process to the liquid extract sequentially; and   (9) using a rotary evaporating process to the product obtained from the step (8), so as to obtain an intermediate product.   

     Furthermore, the following steps can be used for making another intermediate product of clear crystalline material.
     (10) dissolving the intermediate product from step (9) in 60 m acetic acid;   (11) adding 1 mL of concentrated hydrochloric acid (12 N) into the solution obtained from the step (10);   (12) letting the solution mixture obtained from the step (11) to react for 2 hours at 120° C. by using a reflux device;   (13) cooling the temperature of the product obtained from the step (12) down to 0° C.;   (14) adding 60 mL hexane into the product obtained from the step (13);   (15) using a Buchner funnel to treat the product obtained from the step (14) with a filtering process, so as to obtain a precipitate;   (16) using hexane to wash the precipitate for 3 times, so as to obtain a solid material;   (17) using dichloromethane/hexane to treat the solid with a recrystallization process for obtaining a clear crystal solid, wherein the clear crystal solid is presented by following chemical formula 1.   

     
       
         
         
             
             
         
       
     
     Furthermore, various exemplary embodiments for the spirally configured cis-stilbene/fluorene hybrid materials of the present invention can be fabricated by treating certain chemical reaction method to the key intermediate product of clear crystalline materials represented by the chemical formula 1, such as Hartwig reaction and Rosemund-VonBarann method. Therefore, the exemplary embodiments 1-6 of the spirally configured cis-stilbene/fluorene hybrid materials are represented by following chemical formula II, chemical formula III, chemical formula IV, chemical formula V, chemical formula VI (comprising VIa, VIb and VIc), and chemical formula VII (comprising VIIa, VIIb and VIIc): 
     
       
         
         
             
             
         
       
     
     In the above-presented chemical formulas, R can be hydrogen group or tert-butyl group, and X is C—H or N group. Moreover, the data of glass transition temperature (T g ), decomposition temperature (T d ), the longest peak wavelength value of absorption spectrum (λ max ), and the longest peak wavelength value of photoluminescence spectrum (PL_λ max ) of the aforesaid embodiments 1-6 are measured and recorded in the following Table (1). From the Table (1), it is able to know that the spirally configured cis-stilbene/fluorene hybrid materials proposed by the present invention have glass transition temperatures (T g ) ranged from 113° C. to 135° C. and decomposition temperatures (T d ) ranged from 384° C. to 420° C. That means these spirally configured cis-stilbene/fluorene hybrid materials possess excellent thermal stability, and are not easy to decompose under high voltage and high current density operation conditions. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE (1) 
               
               
                   
                   
               
               
                   
                   
                 T g   
                 T d   
                 λ max   
                 PLλ max   
               
               
                   
                 Group 
                 (° C.) 
                 (° C.) 
                 (nm) 
                 (nm) 
               
               
                   
                   
               
             
            
               
                   
                 Embodiment 1 
                 125 
                 403 
                 366 
                 431 
               
               
                   
                 (BSB) 
               
               
                   
                 Embodiment 2 
                 135 
                 420 
                 356 
                 435 
               
               
                   
                 (BΦSΦB) 
               
               
                   
                 Embodiment 3 
                 113 
                 384 
                 334 
                 386 
               
               
                   
                 (PSP) 
               
               
                   
                 Embodiment 4 
                 127 
                 398 
                 328 
                 390 
               
               
                   
                 (PΦSΦP) 
               
               
                   
                 Embodiment 5 
                 115-122 
                 400-411 
                 365-368 
                 415-419 
               
               
                   
                 (PySPy) 
               
               
                   
                 Embodiment 6 
                 123-131 
                 412-419 
                 380-385 
                 421-425 
               
               
                   
                 (PyΦSΦPy) 
               
               
                   
                   
               
            
           
         
       
     
     Moreover, the oxidation potential and the redox potential of the embodiments 1-6 of the spirally configured cis-stilbene/fluorene hybrid materials can be measured by way of cyclic voltammetry (CV); therefore, the highest occupied molecular orbital energy level (E HOMO ) and lowest unoccupied molecular orbital energy level (E LUMO ) of the embodiments 1-6 of the spirally configured cis-stilbene/fluorene hybrid materials can also be calculated based on the measured oxidation potential (E 1/2   ox ) and the redox potential (E 1/2   red ). With reference to following Table (2), E 1/2   ox , E 1/2   red , E HOMO , and E LUMO  of the spirally configured cis-stilbene/fluorene hybrid materials are recorded. From the Table (2), the persons skilled in OLED material art are able to know that the spirally configured cis-stilbene/fluorene hybrid materials proposed by the present invention have the E HOMO  ranged from 5.61 eV to 6.0 eV and the E LUMO  ranged from 2.63 eV to 3.0 eV. Moreover, the spirally configured cis-stilbene/fluorene hybrid materials also have the oxidation potentials ranged from 0.81 V to 1.07 V and the redox potentials ranged from −1.65 V to −2.27 V. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE (2) 
               
               
                   
               
               
                   
                 E 1/2   ox   
                 E 1/2   red   
                 Eg 
                 E HOMO   
                 E LUMO   
               
               
                 Group 
                 (V) 
                 (V) 
                 (eV) 
                 (eV) 
                 (eV) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Embodiment 1 
                 0.93 
                 −2.27 
                 3.00 
                 6.0 
                 3.0 
               
               
                 (BSB) 
               
               
                 Embodiment 2 
                 0.87 
                 −2.24 
                 3.00 
                 5.7 
                 2.7 
               
               
                 (BΦSΦB) 
               
               
                 Embodiment 3 
                 1.07 
                 −373 
                 3.24 
                 5.87 
                 2.63 
               
               
                 (PSP) 
               
               
                 Embodiment 4 
                 1.07 
                 −1.65 
                 3.20 
                 5.87 
                 2.67 
               
               
                 (PΦSΦP) 
               
               
                 Embodiment 5 
                 0.84-0.87 
                  −1.9~−1.98 
                 2.91-2.94 
                 5.64-5.67 
                 2.73-2.76 
               
               
                 (PySPy) 
               
               
                 Embodiment 6 
                 0.81-0.84 
                 −1.91~−1.95 
                 2.96-2.98 
                 5.61-5.63 
                 2.63-2.67 
               
               
                 (PyΦSΦPy) 
               
               
                   
               
            
           
         
       
     
     In order to prove that the proposed spirally configured cis-stilbene/fluorene hybrid materials can indeed be applied in OLEDs for being as a hole-blocking type electron transport layer, a plurality of OLED devices for control groups and experiment groups have been designed and manufactured, wherein the constituting layers for the OLED devices are integrated in the following Table (3). 
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE (3) 
               
               
                   
               
               
                   
                   
                   
                 electron 
                 hole 
                 Light 
                 Hole 
                   
               
               
                 Device 
                   
                 bottom 
                 transport 
                 blocking 
                 emitting 
                 transport 
                 top 
               
               
                 Group 
                 substrate 
                 electrode 
                 layer 
                 layer 
                 layer 
                 layer 
                 electrode 
               
               
                   
               
             
            
               
                 Experiment 
                 Al 
                 LiF 
                 BSB 
                 BSB 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 1a 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 BΦSΦB 
                 BΦSΦB 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 1b 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 PSP 
                 PSP 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 2a 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 PΦSΦP 
                 PΦSΦP 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 2b 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 PySPy 
                 PySPy 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 3a 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 PyΦSΦPy 
                 PyΦSΦPy 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 3b 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Control 
                 Al 
                 LiF 
                 BmPyPb 
                 BmPyPb 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 1A 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Control 
                 Al 
                 LiF 
                 DPyPA 
                 DPyPA 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 1B 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Control 
                 Al 
                 LiF 
                 TPBi 
                 TPBi 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 1C 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Control 
                 Al 
                 LiF 
                 Alq3 
                 Alq3 
                 green 
                 TAPC 
                 HIL/ITO 
               
               
                 1D 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 BSB 
                 BSB 
                 green 
                 NPB/HT01 
                 HIL/ITO 
               
               
                 4 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Experiment 
                 Al 
                 LiF 
                 PΦSΦP 
                 PΦSΦP 
                 green 
                 NPB/HT01 
                 HIL/ITO 
               
               
                 5 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Control 
                 Al 
                 LiF 
                 BmPyPb 
                 BmPyPb 
                 green 
                 NPB/HT01 
                 HIL/ITO 
               
               
                 2 
                   
                   
                   
                   
                 phosphorescent 
               
               
                 Control 
                 Al 
                 LiF 
                 ET01 
                 ET01 
                 green 
                 NPB/HT01 
                 HIL/ITO 
               
               
                 3 
                   
                   
                   
                   
                 phosphorescent 
               
               
                   
               
            
           
         
       
     
     In the Table (3), BmPyPb is the abbreviation of 1,3-bis(3,5-dipyrid-3-yl-phenyl)benzene, DPyPA is the abbreviation of 9,10-bis(3-(pyridin-3-yl)phenyl)anthracene, TPBi is the abbreviation of 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene, and Alq 3  is the abbreviation of tris(8-hydroxyquinoline)aluminium(iii). In addition, ET01 is represented by following chemical formula 2″. 
     
       
         
         
             
             
         
       
     
     It is able to know that the materials of Alq 3 , TPBi, BmPyPb, and ET01 recorded in the Table (3) are also used as OLED device&#39;s electron transport layers. Continuously, the turn-on voltage (V on ), the external quantum efficiency (η ext ), the current efficiency (η c ), the power efficiency (η p ), and the maximum luminance (L max ) of the OLED devices have been measured and recorded in the following Table (4). 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE (4) 
               
               
                   
               
               
                 Device 
                 λ max   
                 Von 
                 η ext   
                 η c /η p   
                 L max   
               
               
                 Group 
                 (nm) 
                 (V) 
                 (%) 
                 (%) 
                 (cd/m 2 ) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Experiment 
                 516 
                 4.9 
                 15.6 
                 54.4/34.9 
                 103740 
               
               
                 1a 
               
               
                 Experiment 
                 516 
                 4.9 
                 15.0 
                 52.2/31.7 
                 90735 
               
               
                 1b 
               
               
                 Experiment 
                 516 
                 2.5 
                 11.0 
                 38.0/28.6 
                 116900 
               
               
                 2a 
               
               
                 Experiment 
                 516 
                 2.1 
                 16.7 
                 58.7/43.9 
                 193800 
               
               
                 2b 
               
               
                 Experiment 
                 516 
                 3.0 
                 16.0 
                 53.6/33.6 
                 128500 
               
               
                 3a 
               
               
                 Experiment 
                 516 
                 2.3 
                 10.5 
                 35.5/26.4 
                 105840 
               
               
                 3b 
               
               
                 Control 
                 516 
                 2.5 
                 6.3 
                 22.8/18.0 
                 142100 
               
               
                 1A 
               
               
                 Control 
                 516 
                 3.0 
                 10.2 
                 37.8/24.0 
                 40700 
               
               
                 1B 
               
               
                 Control 
                 516 
                 3.0 
                 6.9 
                 24.7/22.0 
                 37640 
               
               
                 1C 
               
               
                 Control 
                 516 
                 2.8 
                 3.4 
                 11.5/9.7  
                 42140 
               
               
                 1D 
               
               
                 Experiment 
                 516 
                 5.5 
                 10.6 
                 35.9/20.5 
                 24350 
               
               
                 4 
               
               
                 Experiment 
                 516 
                 5.0 
                 11.9 
                 40.7/25.6 
                 40000 
               
               
                 5 
               
               
                 Control 
                 516 
                 4.5 
                 10.8 
                 36.8/25.7 
                 42150 
               
               
                 2 
               
               
                 Control 
                 516 
                 5.5 
                 7.84 
                 27.6/15.8 
                 17700 
               
               
                 3 
               
               
                   
               
            
           
         
       
     
     With reference to the measured data of the green phosphorescent OLED devices in the Table (4), one can find that the OLED devices using single hole transport layer of Experiment 1a-b, Experiment 2a-b and experiment 3a-b show excellent η ext , η c , η p , and L max  and are much superior to the OLED devices using single hole transport layer of Control 1A, Control 1B, Control 1C, and Control 1D. Among them, experiments 1a (BSB), 2b (PΦSΦP), and 3a (PySPy) show the best results, where the η ext  are in a a range of 15.6-16.7%, η c  are in a range of 53.6-58.7 cd/A, η p  are in a range of 33.6-43.9 lm/w, and L max  are in a range of 103740-193800 cd/m 2 . 
     In addition, the measured data also reveal that the OLED devices using single hole transport layer of Experiment 1a-b, Experiment 2a-b, and Experiment 3a-b show excellent η ext , η c , η p , and L max  and are superior to the OLED devices using complex (i.e., double) hole transport layer of Control 1, Control 2 and Control 3. Moreover, the commercial OLED device using complex (double) hole transport layer of Experiment 5 (PΦSΦP) also shows excellent η ext , η c , η p , and L max , which is superior to the OLED devices using complex (i.e., double) hole transport layer of Control 1, Control 2 and Control 3. 
     Furthermore, device life time evaluation test for the green phosphorescent OLEDs have also been completed based on a starting luminance of 10000 cd/cm 2 . Life time evaluation test results reveal that the decay half lifetime (LT 50 ) of the green phosphorescent OLED of Experiment 2a is 14,000 hours. In addition, the decay half lifetime (LT 50 ) for the green phosphorescent OLEDs of Control 1A and Control 3 are respectively measured as 1,000 hours and 20,000 hours. Moreover, after replacing the BmPyPb in the green phosphorescent OLEDs of Control 1A by the TmPyPb, the green phosphorescent OLEDs having the TmPyPb material is measured with the LT 50  of only 210 hours. 
     In order to prove that the proposed spirally configured cis-stilbene/fluorene hybrid materials can indeed be applied in OLEDs for being as a n-type, host material in an phosphorescent red emitting layer, several of OLED devices for a control group and experiment groups have been designed and manufactured, wherein the constituting layers for the OLED devices are integrated in the following Table (5). 
     
       
         
           
               
               
               
               
               
               
               
               
               
             
               
                 TABLE (5) 
               
               
                   
               
               
                   
                   
                   
                 electron 
                 hole 
                   
                 Light 
                 Hole 
                   
               
               
                 Device 
                   
                 bottom 
                 transport 
                 blocking 
                 Host 
                 emitting 
                 transport 
                 top 
               
               
                 Group 
                 substrate 
                 electrode 
                 layer 
                 layer 
                 material 
                 layer 
                 layer 
                 electrode 
               
               
                   
               
             
            
               
                 Expt. 1a 
                 Al 
                 LiF 
                 BSB 
                 3TPYMB 
                 PSP 
                 Red 
                 TAPC 
                 HIL/ITO 
               
               
                 Expt. 1b 
                 Al 
                 LiF 
                 BSB 
                 3TPYMB 
                 PΦSΦP 
                 Red 
                 TAPC 
                 HIL/ITO 
               
               
                 Control 
                 Al 
                 LiF 
                 BΦSΦB 
                 TPBi 
                 CBP 
                 Red 
                 TAPC 
                 HIL/ITO 
               
               
                 1 
               
               
                   
               
            
           
         
       
     
     With reference to the measured data of the red phosphorescent OLED devices in the Table (6), one can find that the OLED devices using single hole transport layer of Experiment 1a-b and 3TPYMB (represented by following chemical formula 3″) as the hole blocking layer show excellent η ext , η c , η p , and L max  and are better than the OLED device using single hole transport layer of Control 1 and TPBi as the hole blocking layer. Among them, experiments 1a (PSP), and 1b (PΦSΦP) show the best results, where the η ext  are in a range of 16.0-16.9%, η c  are in a range of 22.2-25.7 cd/A, η p  are in a range of 23.3-25.4 lm/w, and L max  are in a range of 29600-30520 cd/m 2 . These results are based on a red phoisphorescent device configuration: ITO/PEDOT:PSS/NPB (20 nm)/TCTA (5 nm)/10% Ir(piq)3 or OS1(25 nm)/3TPYMB (50 nm)/LiF/Al, with an emission λ max  of 616 nm and fwhm=76 nm; CIE(x,y)=(0.63,0.36). The overall current and power efficiencies are improved by 48% and 78%, respectively. Wherein the material OS1 is represented by following chemical formula 4″. 
     
       
         
         
             
             
         
       
     
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE (6) 
               
               
                   
               
               
                 Device 
                 λ max   
                 Von 
                 η ext   
                 η c /η p   
                 L max   
               
               
                 Group 
                 (nm) 
                 (V) 
                 (%) 
                 (%) 
                 (cd/m 2 ) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Experiment 
                 616 
                 2.5 
                 16.0 
                 22.2/23.3 
                 29600 
               
               
                 1a 
               
               
                 Experiment 
                 616 
                 2.4 
                 16.9 
                 25.7/25.4 
                 30520 
               
               
                 1b 
               
               
                 Control 
                 616 
                 3.4 
                 16.1 
                 15.8/12.2 
                 5820 
               
               
                 1 
               
               
                   
               
            
           
         
       
     
     Therefore, through above descriptions, the spirally configured cis-stilbene/fluorene hybrid materials for OLEDs proposed by the present invention have been introduced completely and clearly; in summary, the present invention includes the advantages of:
     (1) The spirally configured cis-stilbene/fluorene hybrid materials are spirally-configured cis-stilbene/fluorene derivatives having glass transition temperatures ranged from 110° C. to 135° C., decomposition temperatures ranged from 380° C. to 425° C., reversible electron transport property, and balanced charges motilities.   (2) Moreover, a variety of experimental data have proved that this spirally configured cis-stilbene/fluorene hybrid materials can indeed be used as a hole-blocking type electron-transporter and/or a host material for OLEDs; moreover, the experiment data also reveal that the OLEDs using the spirally configured cis-stilbene/fluorene hybrid materials can indeed be used as the hole-blocking type electron-transporter are able to show excellent external quantum efficiency (η ext ), current efficiency (η c ), power efficiency (η p ), maximum luminance (L max ), and device lifetime performances better than the conventional or commercial OLEDs.   

     The above description is made on embodiments of the present invention. However, the embodiments are not intended to limit scope of the present invention, and all equivalent implementations or alterations within the spirit of the present invention still fall within the scope of the present invention.