In-situ boron doping of chemical-bath deposited CdS thin films

Abstract

In-situ boron doping of CdS using chemical-bath deposition (CBD) is reported. The effect of B doping on optical properties, as well as electrical properties, crystal structure, chemistry, and morphology of CdS films is studied. We present a successful approach towards B doping of CdS using CBD, where a resistivity as low as 1.7 x 10-2 Ω cm and a carrier density as high as 1.91 x 1019 cm?3 were achieved. The bandgap of B-doped films was found to slightly decrease as the [B]/[Cd] ratio in the solution increases. X-ray diffraction studies showed B3+ ions likely enter the lattice substitutionally. A phase transition, due to annealing, as well as induced lattice defects, due to B doping, were detected by micro-Raman spectroscopy and transmission electron microscopy. The chemistry and morphology of films were unaffected by B doping.