Matching maximum power point of gaas solar cells for a photo-rechargeable system with >26% overall efficiency

Abstract

Abstract The rapid development of the Internet of Things and portable/wearable electronic devices has posed increasing demands for handy and efficient off-grid powers. Solar self-powered systems are one of the emerging options, yet their performance is generally not satisfactory. Herein, a rationally designed photo-rechargeable system is constructed by combining highly efficient GaAs solar cells with an array of aqueous Zn-I2 microbatteries (MBs). Through judiciously matching the charging platform of MBs with the maximum power point (MPP) of GaAs solar cells via circuit designs, an unprecedented overall conversion efficiency (η overall) of 26.32% has been achieved. As a proof of concept, the photo-rechargeable system discharges for 1389 seconds in darkness after 1-minute charging under AM 1.5 G, underscoring its potential for the energy supply of future smart devices.