Single sub-microwire solar cells based on the CdS-Cu2S and CdS-ZnS core-shell heterostructures

CdS sub-microwires with diameter of 200 nm were synthesized by a physical evaporation, Cu2S and ZnS were decorated on CdS sub-microwires as shells by immersing the CdS core into Cu+, Zn2+ and S2− solutions, respectively. The single core-shell sub-microwires were separated individually on the regular Au pattern by the photolithography technique, and then two ends of the sub-microwires were well contacted with Au electrodes by using the electron beam lithography. The photovoltaic efficiencies of 4.54% and 1.40% were achieved by CdS-Cu2S and CdS-ZnS core-shell heterostructure under AM 1.5 G illumination, respectively.