Different materials as a cathode modification layer on the impact of organic solar cells

Abstract

Organic thin film solar cells based on conjugated polymer or small molecules have showed an interesting approach to energy conversion since Tang reported a single donor-accepter hetero-junction solar cell. The power conversion efficiency of organic solar cells has increased steadily over last decade. Small-molecular weight organic double heterojunction donor-acceptor layer organic solar cells (OSC) with a structure of indium-tin-oxide (ITO)/CuPc(200A)/C60(400A)/x/Ag(1000A), using CuPc(copper Phthalocyanine)as donor layer, and Alq3(8-Hydroxyquinoline aluminum salt), BCP(Bromocresol purple sodium salt) and Bphen(4'7-diphyenyl-1,10-phenanthroline) as cathode modification layer, respectively were fabricated. The performance of OSC was studied as a function of the different materials as an cathode modification layer to optimize the structure. The current-voltage characteristic of the solar cell under AM1.5 solar illumination at an intensity of 100 mw/cm2 showed that the power conversion efficiency (PCE) was dependent of the different materials of the cathode modification layer. the efficiency along with the different materials as an cathode modification layer will diminish under that standard solar illumination(AM1.5)was obtained. Using a double heterostructure of ITO/CuPc(200A)/C60(400A)/Alq3(60A)/Ag(1000A) with high-vacuum evaporation technology, the efficiency was 0.587%.the efficiency was 0.967% when the material of the cathode modification layer was BCP, with the structure of ITO/CuPc(200A)/C60(400A)/BCP(35A)/Ag(1000A), and the efficiency was 0.742% when the material of the cathode modification layer was Bphen, with the structure of ITO/CuPc(200A)/C60(400A)/ Bphen(50A)/Ag(1000A).Using different materials as a cathode modification layer, it can be seen that the material which matches the energy level could even eventually be able to improve the energy conversion efficiency more.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.