• Ou, Qingdong
• Raga, Sonia R.
• Lin, Xiongfeng
• Deng, Siqi
• Cheng, Yi-Bing
• Rietwyk, Kevin J.
• Weissbach, Anton
• Lu, Jianfeng
• Tan, Boer
• Zhao, Boya
• Voelcker, Nicolas H.
• Mcmeekin, David P.
• Bach, Udo

Abstract

Back-contact electrodes for hybrid organic-inorganic perovskite solar cells (PSCs) eliminate the parasitic absorption caused by the transparent conductive electrodes that are inherent to conventional sandwich-architecture devices. However, the fabrication methods for these unconventional architectures rely heavily on expensive photolithography which limits scalability. Herein, we present an alternative cost-effective microfabrication technique based on microsphere lithography in which conventional photolithography based on photomasks and photoresist is replaced by a close-packed polystyrene microsphere monolayer as the patterning mask for honeycomb quasi-interdigitated back-contact electrodes. A comprehensive comparison between photolithography and microsphere lithography fabrication techniques was conducted. Using microsphere lithography, we achieve highly efficient small-area devices (0.015 cm2) having a stabilized power conversion efficiency (PCE) of 8.6%, twice that previously reported for the honeycomb structure made using photolithography. This microfabrication technique also enabled the fabrication of the largest back-contact PSC devices reported to date, having an active area of 0.75 cm2, with a stabilized PCE of 2.44%.

Topics

• perovskite
• impedance spectroscopy
• lithography
• power conversion efficiency