CdS/CdSe Core–Shell Nanorod Arrays: Energy\nLevel Alignment and Enhanced Photoelectrochemical Performance

Abstract

Novel CdS/CdSe core–shell\nnanorod arrays were fabricated by a chemical bath deposition of CdSe\non hydrothermally synthesized CdS nanorods. The CdS rods were hexagonal\nphase faced and the top of the rod was subulate. After the chemical\nbath deposition approach, CdS nanorod arrays were encapsulated by\na uniform CdSe layer resulting enhanced absorbance and extended absorption\nedges of the films. A tandem structure of the energy bands of CdS/CdSe\nwas also formed as a result of the Fermi level alignment, which is\na benefit to the efficient separation of photogenerated charges. CdS/CdSe\ncore–shell arrays gave a maximum photocurrent of 5.3 mA/cm², which was 4 and 11 times as large as bare CdS and CdSe,\nrespectively.