Review of Interdigitated Back Contacted Full Heterojunction Solar Cell (IBC-SHJ): A Simulation Approach

Abstract

In the race to higher efficiency Si-based solar cells, several novel configurations have been introduced in the last two decades. One of them is the combination of the heterojunction cell with an intrinsic thin amorphous layer (HIT^TM) and the interdigitated back contacted solar cell (IBC). Lammert et al. proposed the IBC concept in 1975. Years later, the HIT concept was introduced by Tanaka et al. This design combines the advantages of moving all metal contacts to the rear side, hence eliminating shading losses, on the one hand, and on the other leveraging the exceptional passivating properties of a-Si:H thin films to the crystalline Si-based material (c-Si) hence reducing considerably the interface recombination. Both approaches when used separately have proven to show the highest efficiency of Si-based cells on the market at 24 % and 24.7 %, respectively. This article reviews the numerical simulations when using the combined design. It also displays the simulations performed by the authors of this chapter. The effect of different parameters on the cell performance was investigated; c-Si substrate related such as doping level, thickness as well as surface related including front and back surface passivation, and a-Si:H layer properties (intrinsic and doped). We conclude by displaying the effect of the back side design.