Divulging the role of Cu doped CdS nanocrystals as an electron acceptor in hybrid solar cells

Herein, Cu doped CdS nanocrystals (NCs) are employed as electron acceptors in hybrid solar cells (HSCs) for the first time. Firstly, undoped and Cu doped CdS NCs with different concentrations (0.15, 0.3, & 0.6 mol %) are synthesized by the heating-up approach. Structural studies exhibited a peak shift towards a higher wavelength due to the replacement of Cd2+ ions by Cu2+ ions. The shape and size of the particles are explicitly changed with respect to Cu concentration. Furthermore, HSCs are fabricated with the device structure of FTO/ZnO/P3HT: PC61BM:Cu doped CdS NCs/MoO3/Ag. The highest power conversion efficiency of 3.1% is achieved at 0.3 mol% of Cu doped CdS NCs. It is apparent that Cu dopant played a decisive role in the properties of CdS NCs as well as HSCs performance. Therefore, this work unveils the importance of doping and a new strategy to enhance the performance of the HSCs.