Heterojunetion with intrinsic thin layer (HIT) solar cells fabricated on p-type silicon substrates usually demonstrate inferior performance than those formed on n-type substrates. The influence of various structure parameters on the performance of the c-Si(p)based bifacial HIT solar cell, i.e., the TCO/a-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/a-Si:H(p(+))/TCO solar cell, was investigated in detail by computer simulation using the AFORS-HET software. The work function of the transparent conductive oxide was found to be a key factor to affect the solar cell performance. Detailed influence mechanisms were analysed. Accordingly, the design optimization of the bifacial HIT solar cells on c-Si(p) substrates was provided. (c) 2008 Elsevier B.V. All rights reserved.