Spray pyrolysed In2S3 thin films: A potential electron selective layer for large area inverted bulk-heterojunction polymer solar cells

In this paper, we report the results of investigations on the potential of spray pyrolysis technique in depositing electron selective layer over larger area for the fabrication of inverted bulk-heterojunction polymer solar cells. The electron selective layer (In2S3) was deposited using spray pyrolysis technique and the linear heterojunction device thus fabricated exhibited good uniformity in photovoltaic properties throughout the area of the device. An MEH-PPV:PCBM inverted bulk-heterojunction device with In2S3 electron selective layer (active area of 3.25 × 3.25 cm2) was also fabricated and tested under indoor and outdoor conditions. From the indoor measurements employing a tungsten halogen lamp (50 mW/cm2 illumination), an open-circuit voltage of 0.41 V and a short-circuit current of 5.6 mA were obtained. On the other hand, the outdoor measurements under direct sunlight (74 mW/cm2) yielded an open-circuit voltage of 0.46 V and a short-circuit current of 9.37 mA.