Non-Equilibrium Green Functions Approach to Study Transport Through a-Si:H/c-Si Interfaces

Abstract

The microscopic mechanisms of transport and recombination mechanisms in silicon heterojunction solar cells are still poorly understood. The purpose of the present work is to understand the transport mechanisms underlying photovoltaic devices based on silicon heterojunction technology by simulating at atomistic resolution amorphous-crystalline heterointerfaces. We have used classic molecular dynamics simulations to build up realistic c-Si/a-Si:H/c-Si interface at different temperatures. The ab initio characterization has been executed on selected configurations to monitor the electronic properties of the c-Si/a-Si:H/c-Si interface. The electron transmission is calculated at different temperatures based on the non-equilibrium Green functions approach and its behavior is correlated to the evolution of the intragap states. The whole outlined process will allow designing more efficient silicon solar cells belonging to the silicon heterojunction technology.