Ether-Soluble Cu 53 Nanoclusters as an Effective Precursor of High-Quality CuI Films for Optoelectronic Applications

Abstract

An effective strategy is developed to synthesize high-nuclearity Cu clusters, [Cu 53 (RCOO) 10 (C≡CtBu) 20 Cl 2 H 18 ] + (Cu 53 ), which is the largest Cu I /Cu 0 cluster reported to date. Cu powder and Ph 2 SiH 2 are employed as the reducing agents in the synthesis. As revealed by single-crystal diffraction, Cu 53 is arranged as a four-concentric-shell Cu 3 @Cu 10 Cl 2 @Cu 20 @Cu 20 structure, possessing an atomic arrangement of concentric M 12 icosahedral and M 20 dodecahedral shells which popularly occurs in Au/Ag nanoclusters. Surprisingly, Cu 53 can be dissolved in diethyl ether and spin coated to form uniform nanoclusters film on organolead halide perovskite. The cluster film can subsequently be converted into high-quality CuI film via in situ iodination at room temperature. The as-fabricated CuI film is an excellent hole-transport layer for fabricating highly stable CuI-based perovskite solar cells (PSCs) with 14.3 % of efficiency.