Optimisation of High Efficiency AlGaAs MQW Solar Cells

TL;DR

This paper explores optimization strategies for GaAs/AlGaAs multi-quantum well solar cells, addressing material challenges and proposing a structure that enhances spectral response and efficiency.

Contribution

It introduces an optimized GaAs/AlGaAs MQW solar cell design with improved spectral response and voltage performance, overcoming material limitations.

Findings

Enhanced spectral response through three proposed mechanisms.

Experimental evidence of increased open circuit voltage.

Proposed structure achieves higher efficiency potential.

Abstract

The GaAs/AlGaAs materials system is well suited to multi-bandgap applications such as the multiple quantum well solar cell. GaAs quantum wells are inserted in the undoped AlGaAs active region of a pin structure to extend the absorption range while retaining a higher open circuit voltage than would be provided by a cell made of the well material alone. Unfortunately aluminium gallium arsenide (AlGaAs) suffers from poor transport characteristics due to DX centres and oxygen contamination during growth, which degrade the spectral response. We investigate three mechanisms for improving the spectral response of the MQW solar cell while an experimental study of the open circuit voltage examines the voltage enhancement. An optimised structure for a high efficiency GaAs/AlGaAs solar cell is proposed.