Numerical simulation of heterojunction solar cells is a useful approach to investigate the
inner physics of the devices, and can be implemented by simulation tools today. An intra-
band tunneling model has been described previously and applied to some heterojunction
devices. However, the commonly used algorithm for solving the associated equations, the
Gummel method, fails in the case of high recombination rates such as in amorphous Si solar
cells. In this work, we present an improved algorithm that enhances convermicmgence when …