Efficient Planar Perovskite Solar Cells via a Sputtered Cathode

Abstract

Perovskite solar cells (PSCs) attract great attention due to their low cost and high efficiency. In general, the Au cathode, a key component in PSCs, is prepared via an uneconomic vacuum thermal deposition method. Instead, the sputtering deposition method is much more economic and faster. However, it is generally thought that the organic hole transport layer such as 2,2′,7,7′‐tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9′‐spirobifluorene (Spiro‐OMeTAD) can be easily damaged by the high energy plasma during the sputtering process. Thus, the performance of the PSCs greatly decreases. Herein, the structure of the planar PSCs is carefully manipulated by matching the thickness of Spiro‐OMeTAD layer and the Au film. With the further engineering of the interface of the Au/Spiro‐OMeTAD, the planar PSCs with the sputtered Au cathode exhibit a highly reproducible average efficiency of 17.6% ± 0.8%, with the best efficiency of 18.3%. In addition, the Cu electrode is demonstrated by the sputtering method. Finally, the Au sputter deposition is scaled up to make a high efficiency (14.7%) 10 × 10 cm2 module. This demonstrates well that the sputtering deposition of the metal cathode is an effective way for the fabrication of high efficient PSCs for future industrialization.