Perovskite Solar Cells Employing Molecularly Engineered Zn(II) Phthalocyanines as Hole-transporting Materials

Amino donor groups-substituted zinc(II) phthalocyanines (ZnPcs) BI25, BL07 and BL08 were obtained via cyclotetramerization of suitable phthalonitriles that were synthesized by Pd catalyzed amination reaction between 4-iodophthalonitrile and a selected secondary amine. The BI25, BL07 and BL08 ZnPcs were characterized using spectroscopic and electrochemical methods, and used as hole transporting layer in perovskite solar cells. The open circuit voltage (V-OC) of perovskite solar cell devices reached close to 1 V, and the short-circuit current density (J(SC)) values evaluated from J-V curves were 16.2, 8.42, and 16.9 mA/cm(2), respectively, demonstrating influence of the HOMO levels of ZnPcs. A power conversion efficiency of 11.75% was obtained in the case of BI25, which is the highest value ever reported using ZnPcs as HTMs in perovskite solar cells with traditional device geometry. (C) 2016 Elsevier Ltd. All rights reserved.