Preparation And Properties Of Origanic Full-color Photodetector

Organic photodetector(OPD)has the advantages of low cost,ultra-thin,simple pre-paration process and so on.It has become one of the hot spots in recent years.Howe-ver,the current response of the device to the long wavelength band is insufficient,and its response range is difficult to cover the entire visible region.In order to broaden the spectral response range of the device and realize the total primary color response,this paper studies the narrow spectrum response range of the active layer.In the research process,a kind of detection device with full primary color response is fabricated by using the structure of plane and bulk heterojunction.The structure is:ITO/PEDOT:PSS(35nm)/P3HT/PBDT-TT-F:PCBM/Li F(1nm)/Al(100nm).In this case,the PBDTT-F:PCBM heterojunction film is used as the active layer of the device to respon-d to red light.The P3HT thin film responds to the blue-green light in the form of pla-nar heterojunction with the PCBM in the active layer.First,a photodiode based on the P3HT/PCBM planar heterojunction was prepared in order to determine the film thicknes-s of the P3HT pre-absorption layer.When the thickness of the P3HT film is 25nm,the device performance is better.The photocurrent density is 0.475m A/cm²and the optical response is 94.8m A/W at-1V.After the device is annealed at 120?,the photocurrent density is improved Is 0.607m A/cm²,and the corresponding light responsivity is 121.1m A/W.So P3HT film thickness of 25nm,annealed at 120?,the device has a strong response to shortwave light.Then,in order to determine the thickness and the donor receptors'ratio of the PBDT-TT-F:PCBM main active layer,a photodiode based on PBDT-TT-F:PCBM heterojunction was prepared.When the content of the active layer is 95nm,the device has better performance when the mixing ratio is 1:1.5,the device has a photocurrent density of0.349m A/cm²and a light response of 87.2m A/W at-1V bias voltage.So the device active layer thickness of 95nm,blending ratio of 1:1.5,the long wave has a strong response.Finally,on the basis of the above research,the pre-absorption layer thickness and the active layer blending ratio of the organic whole-color photodetector were optimized.When the thickness of the front absorbent layer is 20nm,the performance of the main active layer is better when the acceptor blend ratio is 1:1.5,and the device is further annealed at 120?.The performance is further improved by:-1V bias voltage,dark The current density is5.95×10^-4m A/cm²,the red current density is 0.328m A/cm²,the green current density is0.463m A/cm²,the blue current density is 0.439m A/cm²,the corresponding optical responsivity and the specific detection rate are respectively 82.0m A/W and 4.2×10¹⁰Jones,92.6m A/W and4.7×10¹⁰Jones,87.8m A/W and 4.5×10¹⁰Jones.So the device optimization,the entire visible light area of the light have a better response.This paper has adopted the choice of materials and the use of mixed structure to achieve the response of the device to the whole color light,the future of visible light detection and image sensor research has some guiding significance.