Solutionāprocessed CuSCN serving as hole transport, electron reflecting layer (HTL, ERL) and Cu dopant source for CdSe/CdTe thināfilm solar has demonstrated high power conversion efficiency (PCE) of ~17%. Two types of solvent, diethyl sulfide (DES) and aqueous ammonia (NH4OH), are explored to deposit CuSCN on CdTe, and both can enhance the performance of CdSe/CdTe solar cells. However, NH4OH solvent is less toxicity, leading to a smoother surface than DES solvent, enabling the deposition of ultraāthin CuSCN layer and avoiding the high cost of DES. Temperatureādependent currentāvoltage (JāVāT) and capacitanceāvoltage (CāVāT) measurements reveal that the use of CuSCN HTL increases hole concentration in CdTe absorber and significantly reduces backācontact barrier height. High power conversion efficiency is achievable with the optimal thickness of the CuSCN layer. Our results demonstrate solutionāprocessed CuSCN HTL for enhancing the efficiency and reducing the cost of CdTe thināfilm solar cells.