Due to a strong inversion layer at the a-Si:H/c-Si interface, there are errors in the determination of the band offsets by usual capacitance-voltage (C-V) measurements. An improved C-V measurement was presented to correct the errors by a modification to the apparent diffusion potential Vint. In this paper, the improved C-V measurement is used to characterize the band offsets in a-Si:H/c-Si heterojunctions with a good precision. The modified apparent diffusion potential is determined from Vint and the minority carrier density at the c-Si interface deduced from the coplanar conductance measurements. The value of δEC=0.17±0.04eV between a-Si:H and c-Si is found by the improved C-V measurement with a precise determination of the band offsets.
Nie, G. Z., Zhong, C. L., Luo, L. E., & Xu, Y. (2015). A modification of usual C-V measurement to more precisely characterize the band offsets in a-Si:H/c-Si heterojunctions. Results in Physics, 5, 286–289. https://doi.org/10.1016/j.rinp.2015.10.002