The Effects of Geometry on a-Si:H Solar Cell Performance

TL;DR

This paper models how 3D nanostructures influence the performance of a-Si:H solar cells, highlighting the importance of light absorption in non-planar geometries and comparing simulations with experimental results.

Contribution

It introduces a simulation model for 3D nano-coaxial and hemispherical a-Si:H solar cells and analyzes the impact of geometry on their performance.

Findings

Nanostructure geometry significantly affects light absorption.

Simulations align closely with experimental nanocoaxial solar cell results.

Optimal layer thicknesses improve power efficiency.

Abstract

We present a model for simulating performance of 3D nano -coaxial and -hemispherical thin film solar cells. The material system considered in these simulations is hydrogenated amorphous silicon (a-Si:H), with solar cells fabricated in an n-i-p stacking architecture. Simulations for the performance of the planar a-Si:H device are compared against simulations performed using SCAPS-1D and found to be in close agreement. Electrical and optical properties of devices are discussed for the respective geometries. Maximum power point efficiencies are plotted as a function of i-layer thickness for insight into optimizing spatial parameters. Simulation results show that while geometrical changes in the energy band diagram impact charge carrier collection, a-Si:H solar cell performance is most significantly impacted by light absorption properties associated with nanoscopic arrays of non-planar structures. We compare our simulations to results of fabricated nanocoaxial a-Si:H solar cells and infer the mechanisms of enhanced absorption observed experimentally in such solar cells.