Raytracing and electromagnetic 2-D simulations of the EQE of a-Si:H thin-film solar cells

Thin-film amorphous silicon solar cells depend on light confinement techniques to improve their efficiency. The dual nature of light (wave-particle) compels the use of advanced simulation tools to model these optic phenomena. In the present research work we obtained the external quantum efficiency curve of a degraded cell following two methods: first considered light as a particle and subsequently, simulated it as a wave. The first case consisted of a Monte Carlo raytracing simulation, whereas in the second one we employed an electromagnetic wave finite-difference time-domain software, which solves thoroughly Maxwell equations. The fitting with the experimental is overall good with both procedures. Nonetheless, the interference effects can only be seen with the second tool.

keywords: Raytracing, electromagnetic wave, EQE, a-Si:H solar cells