Investigation of Carrier Recombination Dynamics of InGaP/InGaAsP Multiple Quantum Wells for Solar Cells via Photoluminescence

TL;DR

This study investigates the carrier recombination dynamics in InGaP/InGaAsP quantum wells using photoluminescence, revealing low non-radiative recombination and high radiative efficiency, which explains features in related solar cells.

Contribution

First detailed analysis of carrier recombination dynamics in InGaP/InGaAsP MQWs using PL and time-resolved PL.

Findings

InGaP/InGaAsP MQWs exhibit very low non-radiative recombination.

High radiative efficiency observed in MQWs.

Small conduction band confinement potentials contribute to observed features.

Abstract

The carrier recombination dynamics of InGaP/InGaAsP quantum wells are reported for the first time. By studying the photoluminescence (PL) and time-resolved PL decay of InGaP/InGaAsP multiple-quantum-well(MQW) heterostructure samples, it is demonstrated that InGaP/InGaAsP MQWs have very low non-radiative recombination rate and high radiative efficiency compared to the control InGaP sample. Along with the analyses of PL emission spectrum and external quantum efficiencies, it suggests that this is due to small confinement potentials in the conduction band but high confinement potentials in the valence band. These results explain several features found in InGaP/InGaAsP MQW solar cells previously.