ELECTRICAL AND PHOTOVOLTAIC PROPERTIES OF A THREE-LAYERED ORGANIC SOLAR CELL WITH AN ENLARGED PHOTOACTIVE REGION OF CODEPOSITED DYES

摘要

Three-layered organic solar cell with an interlayer of codeposited dyes of p-type Copper phthalocyanine (CuPc) and n-type 5,10,15,20-Tetra (4-Pyrydil)21H,23 H-Porphine (TPyP) between the respective dyes layers, was prepared and characterised. The analysis of their dark current-voltage (I - U) characteristics at room temperature with respect to the elucidation of conduction mechanisms and evaluation of the cell parameters has been presented. The results suggest that for ITO/CuPc/(CuPc+TPyP)/TPyP/Al cell the conduction mechanism for voltages between 0.1 V and 0.8 V can be described by a modified Shockley equation from which the values obtained for R_s, R_(sh), n and I_0 are 5.82 MΩ, 2 GΩ, 2.74 and 6.2 x 10~(-13) A respectively. The analysis of photovoltaic properties, shows that the photocurrent of three-layered cells is about ten times larger than that of a double layered cell, due to the efficient carrier photogeneration in the codeposited layer. The fill factors for different wavelengths and light intensities ranging from 0.2 to 0.32 have been obtained which are larger than that of a double-layered cell. The best power conversion efficiency reached 0.9% under low monochromatic light of 10 (μW)/(cm~2) at 430 nm.