Fabrication and Optimization of Polymer Solar Cells Based on P3HT:PC70BM System

Abstract

Efficient bulk heterojunction (BHJ) polymer solar cells (PSCs) based on P3HT:PC70BM were fabricated by optimizing the processing parameters. The optimized thickness and annealing temperature have been found to be about 200 nm and 130°C. The effect of cathode interfacial layers on device performance is related to the formation of interfacial dipole. Furthermore, the effect of optimum ZnO interfacial thickness (30 nm) on device performance is attributed to good interfacial conductivity and its optical property. The metal electrode deposited in the slow rate has a better influence on device performance. Based on these optimal conditions, the best power conversion efficiency (PCE) of 3.91% was obtained under AM 1.5G and 100 mW/cm2 illumination. This detailed investigation provides an important reference for the fabrication and optimization of polymer photovoltaic devices.