Preparation of CuI particles and their applications in carbon nanotube-Si heterojunction solar cells

Abstract

Copper iodide (CuI) has good electrical conductivity and is usually used as hole-injector, collector and transporter in solar cells. CuI particles are prepared on silicon wafer by metal-assisted etching method in Cu(NO3)2/HF solution and then iodizing in I2/ethanol solution. The size and density of the CuI particles are well controlled by tuning the etching time in Cu(NO3)2/HF solution. It forms a CNT–CuI–Si solar cell when a carbon nanotube (CNT) film covers on the Si substrate modified by CuI particles. The efficiency of the CNT–Si heterojunction cell modified by CuI particles reaches 6% in the initial test. The quantum efficiency of the CNT–Si cell with CuI modification is higher than that without CuI modification, which shows that CuI particles can enhance hole-collecting and transporting ability in the CNT-Si heterojunction solar cell.