Simulation of the Electrical Parameters of Organic Photovoltaic Cells under QUCS and GPVDM Software

Abstract

Polymer solar cells have attracted much attention during the last years due to their lowerfabrication cost and possibility of using flexible substrates. Various parameters contribute to the stability of theperformances of organic solar cells: the configuration or the structure of the cells, the materials used in theirelaboration such as the active layer, the hole transport layer, the electron transport layer and the electrodecontact. This work represents the modelling and simulation of organic solar cells using two software: QuiteUniversal Circuit Simulator, QUCS and General-Purpose Photovoltaic Device Model, GPVDM. First, anequivalent circuit model constituted from one diode, a series and shunt resistance, and a photocurrent generatorhave been used, this circuit is simulated under QUCS. The simulated results as function of different parameterssuch as series resistance, temperature of the cell, the ideality factor and current saturation are given. Thecurrent density as function of voltage J-V characteristics of the organic cell obtained from the experimentalresults are compared to the simulated one, results show that the curve with Rs=10Ω correspond to theexperimental one, the ideality factor obtained by simulation of the organic cell is 1.2, which corresponds torecombination assisted by the traps levels. Second, we discuss the different structures of organic solar cells andthe role of the interface layer used as hole transport layer or electron transport layer. The effect of the thicknessand the type of the interfacial layers is simulated under GPVDM. The best efficiency is obtained in the case ofcell using aluminum-doped zinc oxide (AZO) as electron transport layer and copper oxide (Cu2O) as holetransport layer. The optimized cell is of the type: ITO/AZO (40 nm)/P3HT:PCBM (200 nm)/Cu2O (20 nm)/Ag,with a best power conversion efficiency of 5%.