An InGaN/CuSCN photoanode for visible-light photoelectrochemical photodetectors with over tenfold enhanced photocurrent

CuSCN, a wide-bandgap p-type semiconductor, is employed to boost the photocurrent of an InGaN photoanode of a photoelectrochemical photodetector. The extension of the upward energy band bending in InGaN into the depletion region of CuSCN, governed by the respective surface states to form an interface dipole, enhances photocarrier separation to increase the photocurrent by more than an order of magnitude compared to that of the bare InGaN photoanode. This is achieved by the combined optimization of the hole concentration and layer thickness controlled in the adopted electrodeposition process by the electrolyte composition and deposition time. The basic photodetector parameters, including responsivity, specific detectivity, and response time, are also evaluated.