Query: n type organic semiconductor

title: Conductivity and Photoconductivity of a p Type Organic Semiconductor under Ultrastrong Coupling.
abstract: During the past decade, it has been shown that light matter strong coupling of materials can lead to modified and often improved properties which has stimulated considerable interest. While charge transport can be enhanced in n type organic semiconductors by coupling the electronic transition and thereby splitting the conduction band into polaritonic states, it is not clear whether the same process can also influence carrier transport in the valence band of p type semiconductors. Here we demonstrate that it is indeed possible to enhance both the conductivity and photoconductivity of a p type semiconductor rr P3HT that is ultrastrongly coupled to plasmonic modes. It is due to the hybrid light matter character of the virtual polaritonic excitations affecting the linear response of the material. Furthermore, in addition to being enhanced, the photoconductivity of rr P3HT shows a modified spectral response due to the formation of the hybrid polaritonic states. This illustrates the potential of engineering the vacuum electromagnetic environment to improve the optoelectronic properties of organic materials.

title: An OTFT based on titanium phthalocyanine dichloride: A new p type organic semiconductor
abstract: A p type organic thin film transistor (OTFT) was fabricated based on an axially substituted phthalocyanine (titanium phthalocyanine dichloride: TiCl2Pc) Molecular energies and atomic charge distributions of a series of axially substituted metal phthalocyanines were studied using measurements of their electrochemical properties and X ray photoemission spectroscopy, respectively. Based on these measurements, the relationship between the charge carrier transport types of the phthalocyanines in OTFTs and their substituted groups (metal and axial ligands) are discussed. The axially substituted electron withdrawing groups can effectively lower the LUMO energy and increase the charge separation, contributing to the realization of n type behavior, e.g. in SnCl2Pc. The electronegativity of the metal also affects the LUMO energies and charge distributions, such that TiCl2Pc is a p type semiconductor.

title: An A p D p A Type Organic Semiconductor Based Optoelectrical Device With Photo Response and Optical Memory Behaviors
abstract: A novel photoactive semiconductor (named as IDTOT 4F) with an A p D p A type configuration is synthesized. It contains an electron donating fused ring (D) as the core flanked with two p spacers and is end capped with two electron withdrawing units (A) The intramolecular charge transfer effect endows IDTOT 4F with strong and broad light absorption and a relatively narrow band gap (1.46 eV) Thin film optoelectrical devices based on IDTOT 4F exhibit both n type and p type switching behaviors. Besides, the p channel device shows significantly photoresponsive performance with the maximum P (photo/dark current ratio) R (photoresponsivity) and D* (detectivity) values of around 60, 0.07 AW 1, and 2.5 x 1010 Jones, respectively. Further, IDTOT 4F based optoelectrical devices exhibit good optical memory characteristics with a time constant t 1 of 4.6 h, indicating its applicability to nonvolatile optical memory devices. The results provide new insights into the photoresponsive behavior of fused ring semiconductors and pave the way for the design of nonvolatile optical memory devices.

title: Use of doping to achieve low contact resistance in bottom gate top contact type organic transistor with liquid crystalline organic semiconductor, Ph BTBT 10
abstract: We have investigated the characteristics of bottom gate and top contact type field effect transistors fabricated with polycrystalline thin films of a liquid crystalline organic semiconductor, 2 decyl 7 phenyl benzothienobenzothiophene (Ph BTBT 10) with a p type dopant, tetrafluoro tetracyano quinodimethane (F4 TCNQ) We found that the contact resistance between the semiconductor and electrode was reduced from 3.0 kO cm to 1.2 kO cm by contact doping with F4 TCNQ, and to 0.9 kOcm by subsequent thermal annealing of the films, in which the F4 TCNQ dopant diffused from the surface to the interior of the Ph BTBT 10 thin film. In addition, we found that contact doped and thermally annealed devices showed higher mobility and smaller threshold voltage in short channel devices compared to pristine devices. We conclude that thermal diffusion of dopants to improve FET performance is an important technique.

title: Improving Bias Stress Stability of p Type Organic Field Effect Transistors by Constructing Electron Injection Barrier at the Drain Electrode/Semiconductor Interfaces.
abstract: Bias stress instability has been a challenging problem and a roadblock for developing stable p type organic field effect transistors (OFETs) This device instability is hypothesized as due to electron correlated charge carrier trapping, neutralization and recombination at semiconductor/dielectric interfaces and in semiconductor channels. Here in this paper a strategy is demonstrated to improve the bias stress stability by constructing multi layered drain electrode with energy level modification layers (ELMLs) Several organic small molecules with high LUMO energy levels are experimented as ELMLs. The energy level offset between the Fermi level of the drain electrode and the LUMOs of the ELMLs are shown to construct interfacial barrier, which suppresses electron injection from the drain electrode into the channel leading to significantly improved bias stress stability of OFETs. The mechanism of the ELMLs on the bias stress stability is studied by quantitative modeling analysis of charge carrier dynamics. Of all injection models evaluated, it is found that Fowler Nordheim tunneling describes best the observed experimental data. Both theory and experimental data show that, by using the ELMLs with higher LUMO levels, the electron injection can be suppressed effectively and the bias stress stability of p type OFETs can thereby be improved significantly.

title: Solar Powered Organic Semiconductor Bacteria Biohybrids for CO2 Reduction into Acetic Acid.
abstract: Photosynthetic biohybrid systems have emerged as a promising platform for solar to chemical conversion by integrating excellent light harvesting ability of semiconductors with the synthetic capability of biological cells. How to enhance the utilization of solar energy, hole/electron separation efficiency and the electron transfer between the semiconductor and biological cells is crucial to develop high performance photosynthesis platforms. In this work, we developed an organic semiconductor bacteria biohybrid photosynthetic system, which could efficiently realize CO 2 reduction to produce acetic acid through non photosynthetic bacteria Moorella thermoacetica As the photosensitizers, both cationic electron transporting n type) perylene diimide derivative (PDI) and hole transporting p type) poly(fluorene co phenylene) (PFP) were coated on the bacteria surface to form p n heterojunction (PFP/PDI) layer, affording higher hole/electron separation efficiency. The p conjugated semiconductors possess excellent light harvesting ability and biocompatibility, and more importantly, the cationic side chains of organic semiconductors could intercalate into cell membrane, ensuring the efficient electron transfer to bacteria. As a result, Moorella thermoacetica can harvest photoexcited electrons from the PFP/PDI heterojunction, which can drive the Wood Ljungdahl pathway to synthesize acetic acid from CO 2 under illumination. The efficiency of this organic biohybrid is 1.6% which is comparable to those of reported inorganic biohybrid systems. This work opens a new avenue to explore bioenergy application of organic semiconductors, and also provides a convenient biomanufacturing approach to design organic semiconductor bacteria biohybrids for efficient solar to chemical conversion.

title: Mizoroki Heck type reactions and synthesis of 1,4 dicarbonyl compounds by heterogeneous organic semiconductor photocatalysis
abstract: We report the synthesis of 1,4 dicarbonyl compounds and substituted alkenes (Mizoroki Heck type coupling) starting from secondary and tertiary alkyl halides and vinyl acetate or styrene derivatives using visible light photocatalysis. The protocol uses mesoporous graphitic carbon nitride (mpg CN) as a heterogeneous organic semiconductor photocatalyst and Ni(II) salts as Lewis acid catalysts. Detailed post characterization of the heterogeneous material has been carried out to support the proposed catalytic cycle. Apart from high functional group tolerance, mild reaction conditions, scalability as well as easy recovery and reuse of the mpg CN photocatalyst provide a practical solution to these widespread transformations in terms of sustainability and efficiency and this methodology is recommended for applications in academic and industrial synthesis.

title: Anisotropic charge carrier transport of optoelectronic functional selenium containing organic semiconductor materials
abstract: Organic semiconductors (OSCs) materials are currently under intense investigation because of their potential applications such as organic field effect transistors, organic photovoltaic devices, and organic light emitting diodes. Inspired by the selenization strategy can promote anisotropic charge carrier migration, and selenium containing compounds have been proved to be promising materials as OSCs both for hole and electron transfer. Herein, we now explore the anisotropic transport properties of the series of selenium containing compounds. For the compound containing SeSe bond, the SeSe bond will break when attaching an electron, thus those compounds cannot act as n type OSCs. About the different isomer compounds with conjugated structure, the charge transfer will be affected by the stacking of the conjugated structures. The analysis of chemical structure and charge transfer property indicates that Se containing materials are promising high performance OSCs and might be used as p type, n type, or ambipolar OSCs. Furthermore, the symmetry of the selenium containing OSCs will affect the type of OSCs. In addition, there is no direct relationship between the R groups with their performance, whether it or not as p type OSCs or n types. This work demonstrates the relationship between the optoelectronic function and structure of selenium containing OSCs materials and hence paves the way to design and improve optoelectronic function of OSCs materials.

title: Signature of p type semiconductor features in paper based back gate metal organic framework thin film transistors
abstract: A kind of continuous flexible paper substrate thin film transistors (TFTs) of the ratio of a controllable length to width nickel (Ni) two dimensionally connected metal organic frameworks, Ni TCNQ (TCNQ 7, 7, 8, 8 tetracyanoquinodimethane) has been prepared skillfully by using all ink jet printing Ni(NO3)2*6H2O and the TCNQ hydrothermal interface in situ reaction method. The structure analysis of Ni TCNQ on copper electrodes was revealed by combining transmission electron microscope and powder x ray diffraction techniques, indicating that it has a lamellar and porous structure. The morphology and structure of the transistor channel are stacked up by nanosheets of 2D lattice of [Ni(C12H4N4)2]n, which is further verified by scanning electron microscope, FT IR, and x ray photoelectron spectroscopy. I V characteristics show that electrical behaviors of the p type junctionless TFT are fabricated at room temperature.

title: Schottky junction photodiode based on graphene organic semiconductor heterostructure
abstract: The isolation of graphene on an insulating substrate has provided new opportunities for the fabrication of electronic devices with radically new geometries and structures. The use of single layer graphene as an electrode has enabled the development of novel electronic device architectures that exploit the unique atomically thin structure of the material, which also includes a low density of states at its charge neutrality point. In this work, we present the first example of a vertical Schottky junction photodiode based on the graphene organic semiconductor metal heterostructure. The n type N,N' dioctyl 3,4,9,10 perylenedicarboximide (PTCDI C8) organic semiconductor was thermally deposited onto chemical vapor deposition (CVD) grown single layer graphene. The tunable Schottky injection barrier permitted tuning of the diode rectification ratio by more than two orders of magnitude upon application of gate biases, which increased the photocurrent but suppressed the dark current of the photodiodes. Tuning of the photovoltaic properties of the devices was also confirmed, indicating that the device architecture based on the work function tunability of graphene could provide a versatile strategy for enhancing the performance of organic photodiodes.