The performance enhancement of an InGaN/GaN multiple-quantum-well solar cell by superlattice structure

An enhanced InGaN/GaN multiple-quantum-well (MQW) solar cell was produced and characterized through the superlattice structure (SLS) insertion. The experiments demonstrated that the conversion efficiency of the fabricated device increased from 0.61 to 1.61%, compared to the device without SLS. The promising result was considered to originate from the SLS insertion. From Raman analysis and theoretical calculation of the electron transmissivity, it was demonstrated that the plane strain of GaN was effectively released when the SLS was inserted and the electron tunneling effect was enhanced. Consequently, the collection of photo-generated electrons was strengthened, which thereby led to the conversion efficiency increase.