Im Sik Han

Influence of Carrier Trap in InAs/GaAs Quantum-Dot Solar Cells

In order to investigate an influence of carrier trap by quantum dots (QDs) on the solar parameters, in this study, the solar cells with InAs/GaAs QD active layers are fabricated, and their characteristics are investigated and compared with those of a GaAs matrix solar cell (MSC). Two different types of QD structures, the Stranski-Krastanow (SK) QD and the quasi-monolayer (QML) QD, have been introduced for the QD solar cells, and the parameters (open-circuit voltage (), short-cirucuit current (), fill factor (FF), conversion efficiency (CE)) are determined from the current-voltage characteristic curves under a standard solar illumination (AM1.5). In SK-QSC, while FF of 80.0% is similar to that of MSC (80.3%), and are reduced by 0.03 V and , respectively. CE is lowered by 2.6% as results of reduced and , which is due to a carrier trap into QDs. Though another alternative structure of QML-QD to be expected to relieve the carrier trap have been firstly tried for QSC in this study, it shows negative results contrary to our expectations.