Improving the performance of Sb2Se3 sensitized solar cells with a versatile CdSe layer modification

Abstract Sb2Se3 with its excellent optical, electrical properties emerging as a promising next-generation light harvesting material has gained immense research interest. However, in the Sb2Se3 photovoltaic devices, the impediment of charge transport within the layered structure dragged down the device performance. Here, for the first time, we reported the air-stabled Sb2Se3 sensitized solar cells (SSCs) modified with CdSe interlayer at the TiO2/Sb2Se3 heterojunction through successive ionic layer adsorption and reaction (SILAR) process. CdSe modification provided the reduced TiO2 work function, enhanced optical absorption and suppressed charge recombination. The short-circuit current density, fill factor and open-circuit voltage of the Sb2Se3 SSCs were all remarkably improved. When CdSe layer with five SILAR cycles was applied, the device power conversion efficiency (PCE) was as high as 1.96%, which was the highest recorded PCE of Sb2Se3 nanoparticle based solar cells. Our work illustrates that interfacial engineering provided a useful route to adjust the interface configuration in Sb2Se3 based solar cell and optoelectronic applications.