Improving the performance of ITO/ZnO/P3HT:PCBM/Ag solar cells by tuning the surface roughness of sprayed ZnO. (October 2015)

• Record Type: Journal Article
• Authors: Geethu, R.; Sudha Kartha, C.; Vijayakumar, K.P.
• Is Part Of: Solar energy. Volume 120(2015)
• Page Start: 65
• Page End: 71
• Publication Date: 2015-10
• Subjects: Chemical spray pyrolysis -- ZnO -- P3HT:PCBM -- AFM -- Solar cell; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2015.06.037
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Simple ZnO/Polymer heterojunction was fabricated. Cost effective solution processing techniques were used for device fabrication. Photovoltaic parameters were tuned by manipulating surface roughness of ZnO layer. Best device fabricated has V oc = 523 mV, J sc = 8.32 mA/cm 2, FF = 37% and η = 1.62%. Large area device having an active area of 6.25 cm 2 was fabricated. Abstract: A simple hetero junction with configuration ITO/ZnO/P3HT:PCBM/Ag was fabricated by employing chemical spray pyrolysis technique for ZnO thin film and spin coating technique for polymer film deposition. Both ZnO and polymer deposition was conducted in ordinary atmospheric conditions. Roughness of ZnO layer was observed to be crucial parameter that determines overall performance of the device. Optimization of surface roughness of ZnO layer for better quality of the device was achieved through variation of spray parameters (viz., substrate temperature and spray rate). AFM analysis was effectively used to explore the surface roughness of ZnO layer. Structural, optical and electrical studies were also done for samples prepared at optimized condition. The best device under this study has open circuit voltage of 523 mV, short circuit current density of 8.32 mA/cm 2, fill factor of 37% and efficiency of 1.62%. In order to demonstrate the potential of chemical spray pyrolysis technique for large area deposition, the optimized deposition conditions for small area (0.03 cm 2 ) cell were extended for large area device (6.25 cm 2 ). Indoor and outdoor measurements were also performed on large area device.