Fabrication, characterizations, and electron transportation from CdS/Cd/Si heterojunctions by the radio frequency magnetron sputtering method

CdS/Cd/Si heterojunctions have been prepared through depositing cadmium nanocrystallites (nc-Cd) and CdS nanocrystallites in turn on the single-crystal silicon wafer by the radio frequency (RF) magnetron sputtering method, which structures have been investigated by XRD and SEM techniques. Moreover, the dark/light current density vs voltage (I–V) and the impedance spectroscopy have been recorded to study the roles of incorporated nc-Cd in the electron transportation. The introduction of nc-Cd into the heterojunctions interface is helpful for the electron transportation at forward voltage. After nc-Cd has been introduced into the interface, the relaxation time, short-circuit current density, and energy conversion efficiency have been enhanced. Those are ascribed to the reduction of the defect concentration due to the introduction of nc-Cd into the interface of CdS/Si heterojunctions.