Abstract:
A structure is formed by putting glass plates between a luminescence generating device and an electron emitting device so that a vacuum is formed in between. After in putting a high-voltage, an electron beam is emitted from the electron emitting device using low power. In the end, silicon quantum dots in the luminescence generating device are excited to generate a white light. The present invention has a good optoelectronic transformation efficiency.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a white-light lamp; more particularly, relates to exciting a luminescence layer having silicon quantum dots by an electron beam to obtain a white light. 
   DESCRIPTION OF THE RELATED ART(S) 
   A first prior art, called “A white light emitting diode,” is proclaimed in Taiwan, comprising a light emitting source, emitting a light having a wavelength between 440 nanometers (nm) to 490 nm; and a phosphor, comprising a yellow phosphor and a red phosphor, where the yellow phosphor is made of (Me 1-x-y Eu x Re y ) 3 SiO 5 ; and the red phosphor is made of Y 2 O 3 :Eu 3+ , Y 2 O 3 :Bi 3+ , (Y,Gd) 2 O 3 :Eu 3+ , (Y,Gd) 2 O 3 :Bi 3+ , Y 2 O 2 S:Bi 3+ , (Me 1-x Eu x )ReS or Mg 3 SiO 4 :Mn. 
   A second prior art is called “A white light emitting diode and a fabricating method thereof”. The second prior art is a white-light emitting diode comprises a print circuit board (PCB), a plurality of white-light emitting diodes (LED), and a controller where the white LEDs are deposed on a side of the PCB; each white LED comprises a substrate, at least one blue LED on the substrate, and a mixed phosphor, mixed with a red phosphor, a green phosphor and a yellow phosphor; the mixed phosphor is covered on the outside of the blue LED; the red phosphor is made of CaS:Eu; the green phosphor is made of SrGa 2 S 4 :Eu or Ca 8 EuMnMg(SiO 4 ) 4 Cl 2 ; the yellow phosphor is made of YAG:Ce or TbAG:Ce; and the controller is deposed on another side of the PCB to apply different current to each white LED to adjust color temperature. 
   A third prior art, “A white-light emitting device and a fabricating method thereof,” is revealed in Taiwan, comprising a LED, a first phosphor and a second phosphor, where the LED emits an ultra-violet light; the first phosphor is excited by the ultra-violet light from the LED to generate a cyan fluorescent light having a wavelength between 470 nm and 500 nm; the first phosphor is made of (Ba 1-x-y Eu x Sr y )MgAl 10 O 17  with x greater than 0 and not greater than 1 and y not smaller than 0 and not greater than 1; the second phosphor is excited by the ultra-violet light from the LED to generate an orange light having a wavelength between 570 nm and 600 nm; the second phosphor is made of (Ca,Eu,Mn)(PO 4 ) 3 Cl; and a white light is obtained by mixing the cyan light and the orange light. 
   A fourth prior art is called “A white light emitting device”, comprising a LED, a first phosphor and a second phosphor, where the LED emits blue light or cyan light; the first phosphor is made of (Y x M y Ce z )Al 5 O 12 ; x plus y equals 3 and x and y not equals to 0; z is smaller than 0.5 and greater than 0; M is Tb, Lu or Yb; Ce is a luminescent center; the first phosphor is excited by the light from the LED to obtain a yellow light having a wavelength between 520 nm and 580 nm; the second phosphor is excited by the light from the LED to obtain a red light having a wavelength between 580 nm and 640 nm; and a white light is obtained by mixing the light from the LED with the yellow light and the red light. 
   Although the above prior arts generate white lights by exciting phosphors with lights, the optoelectronic transformation efficiency is low so that exciting light sources using high power, or thick phosphor layer, are used. Hence, the prior arts do not fulfill users&#39; requests on actual use. 
   SUMMARY OF THE INVENTION 
   The main purpose of the present invention is to excite a luminescence layer having silicon quantum dots by an electron beam from a low-power electron emitting device to obtain a white light. 
   To achieve the above purpose, the present invention is a white-light fluorescent lamp having silicon quantum dots and a fabricating method thereof, where the white-light fluorescent lamp having silicon quantum dots comprises a luminescence generating device, an electron emitting device, at least one separating plate and a high-voltage circuit; the luminescence generating device comprises a first conductive substrate, a luminescence layer having silicon quantum dots, and a metal film; the electron emitting device comprises a second conductive substrate and a nano-carbon tube layer; and the high-voltage circuit comprises a high-voltage source. 
   Therein, the present invention has a fabricating method of the white-light fluorescent lamp having silicon quantum dots, comprising steps of: (a) under a vacuum environment, deposing at least one separating plate between a luminescence generating device and an electron emitting device to form a package structure having a vacuum between the luminescence generating device and the electron emitting device; and (b) adding a high-voltage circuit outside of the package structure, having a high-voltage source with an anode end connecting to a first conductive substrate of the luminescence generating device and a cathode end connecting to a second conductive substrate of the electron emitting device. 
   Accordingly, a novel white-light fluorescent lamp having silicon quantum dots and a fabricating method thereof are obtained. 

   
     BRIEF DESCRIPTIONS OF THE DRAWINGS 
     The present invention will be better understood from the following detailed description of the preferred embodiment according to the present invention, taken in conjunction with the accompanying drawings, in which 
       FIG. 1  is a structural view showing the preferred embodiment according to the present invention; 
       FIG. 1A  is a structural view showing the luminescence generating device; 
       FIG. 1B  is a structural view showing the electron emitting device; 
       FIG. 2A  is a flow view showing the fabricating method; 
       FIG. 2B  is another structural view showing the preferred embodiment; 
       FIG. 3A  is a view showing the first state of use; and 
       FIG. 3B  is a view showing the second state of use. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The following description of the preferred embodiment is provided to understand the features and the structures of the present invention. 
   Please refer to  FIG. 1 , which is a structural view showing a preferred embodiment according to the present invention. As shown in the figure, the present invention is a white-light fluorescent lamp having silicon quantum dots and a fabricating method thereof, where the white-light fluorescent lamp having silicon quantum dots  1  comprises a luminescence generating device  11 , an electron emitting device  12 , at least one separating plate  13  and a high-voltage circuit  14 . 
   Please further refer to  FIG. 1A , which is a structural views showing the luminescence generating device. As shown in the figure, the luminescence generating device  11  comprises a first conductive substrate  111 , a luminescence layer having silicon quantum dots  112 , and a metal film  113 , where the luminescence layer having silicon quantum dots  112  is covered on the first conductive substrate  111  through a chemical vapor deposition or a screen printing process; the metal film  113  is covered on the luminescence layer having silicon quantum dots and is corresponding to the first conductive substrate  111 ; the first conductive substrate  111  is made of a substrate  1111 , which has a transmission rate greater than 90 percents (%) and is covered with an indium tin oxide (ITO) layer  1112 ; the substrate  1111  is made of a glass; the luminescence layer having silicon quantum dots  1112  is obtained through embedding silicon quantum dots, each having a granular diameter between 1 nanometer (nm) and 10 nm, into an organic or inorganic luminescent material by using a physical or chemical method; the inorganic luminescent material is silicon dioxide, silicon nitride or silicon carbide; the metal film  113  is an aluminum film or a gold film; and the metal film  113  is used as a reflective glass and an anode material to increase electron number and to dissipate heat. 
   Please further refer to  FIG. 1B , which is a structural views showing the electron emitting device. As shown in the figure, the electron emitting device  12  comprises a second conductive substrate  121  and a nano-carbon tube layer  122 , where the nano-carbon tube layer  122  is covered on the second conductive substrate  121  through a chemical vapor deposition or a screen printing process; the second conductive substrate  121  is made of a substrate  1211 , which has a transmission rate greater than 90% and is covered with an ITO layer  1212 ; the substrate  1111  is made of a glass or a silicon block; and the nano-carbon tube layer  122  is an electron emitting source. 
   The separating plate  13  is made of a material having a transmission rate greater than 90%; the material is a glass; and the separating plate  13  is located between the luminescence generating device  11  and the electron emitting device  12  to obtain a vacuum. 
   The high-voltage circuit  14  comprises at least one high-voltage source  141 , where an anode end  1411  of the high-voltage source  141  is connected to the first conductive substrate  111  of the luminescence generating device  11  and a cathode end  1412  of the high-voltage source  141  is connected to the second conductive substrate  121  of the electron emitting device  12 . 
   Thus, a novel white-light fluorescent lamp having silicon quantum dots is obtained. 
   Please refer to  FIG. 2A  and  FIG. 2B  which are a flow view showing a fabricating method and another structural view showing the preferred embodiment. As shown in the figures, the fabricating method of a white-light fluorescent lamp having silicon quantum dots comprises the following steps: 
   (a) Forming a package structure  21 : Under a vacuum environment, a luminescence generating device  11 , an electron emitting device  12  and at least one separating plate  13  are adhered to form a package structure  10  by using an adhesive. 
   (b) Adding a high-voltage circuit  22 : A high-voltage circuit  14  is added outside of the package structure  10 , comprising at least one high-voltage source  141 , where an anode end  1411  of the high-voltage source  141  connects to a first conductive substrate  111  of the luminescence generating device  11  and a cathode end  1412  of the high-voltage source  141  connects to a second conductive substrate  121  of the electron emitting device  12 . 
   Thus, a novel white-light fluorescent lamp having silicon quantum dots is obtained. 
   Please refer to  FIG. 3A , which is a view showing the first state of use. As shown in the figure, a white-light fluorescent lamp having silicon quantum dots  1   a  according to the present invention comprises a luminescence generating device  11   a , an electron emitting device  12   a , at least one separating plate  13   a  and a high-voltage circuit  14   a . When a current runs in the high-voltage circuit  14   a , a nano-carbon tube layer  122   a  of the electron emitting device  12   a  emits an energetic electron beam  31   a  to the luminescence generating device  11   a . The electron beam  31   a  penetrates through a metal film  113   a  of the luminescence generating device  11   a  so that silicon quantum dots in a luminescence layer having the silicon quantum dots  112   a  are excited to obtain a visible light source  32   a.    
   Please refer to  FIG. 3B , which is a view showing the second state of use. As shown in the figure, a white-light fluorescent lamp having silicon quantum dots  1   b  according to the present invention comprises a luminescence generating device  11   b , an electron emitting device  12   b , at least one separating plate  13   b  and a high-voltage circuit  14   b , where a grid  1413  is added to the high-voltage circuit  14   b  between the luminescence generating device  11   b  as an anode and the electron emitting device  12   b  as a cathode. When a current runs in the high-voltage circuit  14   b , a nano-carbon tube layer  122   b  of the electron emitting device  12   b  emits an energetic electron beam  31   b  through the grid  1413  so that a field effect is happened between the grid  1413  and the electron emitting device  12   a  as the cathode, and the nano-carbon tube layer  122   b  becomes an electron emission source. The electron beam  31   b  passes through the grid  1413 . Owing to the lowering-down of the electric potential between the grid  1413  and the luminescence generating device  11   b  as an anode, the electron beam  31   b  accelerates to pass through a metal film  113   b  of the luminescence generating device  11   b  and arrives at a luminescence layer having silicon quantum dots  112   b  so that the silicon quantum dots in the luminescence layer having silicon quantum dots  112   b  are excited to obtain a visible light source  32   b.    
   To sum up, the present invention is a white-light fluorescent lamp having silicon quantum dots and a fabricating method thereof, where an electron emitting device generates an electron beam to excite a fluorescent layer to obtain a white light source with an improved optoelectronic transformation efficiency. 
   The preferred embodiment herein disclosed is not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.