Structural, Optical, Photoelectrochemical, and Electronic Properties of the Photocathode CuS and the Efficient CuS/CdS Heterojunction

Abstract

We report a facile synthesis of CuS and CdS nanoparticles using a cheap solution-processed chemical bath method forming heterogeneous nucleation. The optical, structural, photoelectrochemical (PEC), and electronic properties are studied by implementing relevant experimental techniques. The estimated optical band gap of ∼2.10 eV of CuS designates potential application in inexpensive photocatalysis and solar cells. Further, the valence band and conduction band positions of CuS and CdS are evaluated using cyclic voltammetry curves. Narrow conduction and valence band offset potentials measured at the CuS/CdS heterojunction are encouraging factors for the PEC application. The electronic properties are supported by the current density vs potential plots (J-V) with an improved short-circuit current density of 0.71 mA cm-2for the heterojunction compared to bare CuS showing 0.15 μA cm-2. The determined PCE of the heterojunction CuS/CdS is 0.65%.