Electrical and optical properties of boron‐doped nanocrystalline silicon films deposited by PECVD

Abstract Boron‐doped nanocrystalline silicon (nc‐Si:H) films were deposited by plasma‐enhanced chemical vapor deposition (PECVD). A variety of techniques, including X‐ray diffraction (XRD), Raman scattering (RS), UV–Vis–NIR spectroscopy and conductivity measurement were used to characterize the grown materials. Lightly B‐doped samples are well crystallized, while the undoped and heavily doped ones are amorphous. The optical bandgap decreases as the substrate temperature, radio‐frequency (RF) power density, and diborane concentration increase. The influence of many deposition parameters such as diborane concentration, substrate temperature, RF power and deposition pressure on electrical, optical properties, and deposition rate were systemically studied. The optimum combination of deposition parameters was suggested to obtain the appropriate boron‐doped nc‐Si:H thin films that can be applied as a p‐type layer or window‐layer material for silicon thin‐film solar cells.