Copper Thiocyanate Inorganic Hole-Transporting Material for High-Efficiency Perovskite Solar Cells

• Published in: ACS energy letters Vol. 1; no. 6; pp. 1112 - 1117
• Main Authors: Madhavan, Vinod E, Zimmermann, Iwan, Roldán-Carmona, Cristina, Grancini, Giulia, Buffiere, Marie, Belaidi, Abdelhak, Nazeeruddin, Mohammad Khaja
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.12.2016
• ISSN: 2380-8195; 2380-8195
• DOI: 10.1021/acsenergylett.6b00501

In this Letter we show that the mixed perovskite in the form of (FAPbI3)0.85(MAPbBr3)0.15 in combination with CuNCS as p-type hole conductor leads to over 16% power conversion efficiency (PCE) under full sun illumination and yields a remarkable monochromatic incident photon-to-electron conversion efficiency of 85%. The devices displayed a short-circuit current density (J sc) of 21.8 mA/cm2, open-circuit voltage (V oc) of 1100 mV, fill factor (FF) of 0.69, and a PCE of 16.6%. Under similar conditions, the device without CuSCN shows a PCE of 9.5%, with a significant decrease in the J sc (from 21.8 mA/cm2 to 15.64 mA/cm2) and V oc (from 1100 mV to 900 mV). The high J sc with CuSCN is mainly due to the effective charge transfer between perovskite and CuSCN, followed by the fast hole transport through CuSCN to the Au. In comparison, the spiro-OMeTAD reference cells showed efficiencies up to 19.65%. Different from most organic hole-transporting materials is the transparency and high hole mobility of CuSCN, which represent a paradigm shift in perovskite solar cells particularly for tandem solar cells.