Optimization in wide-band-gap quantum dot solar cells

Quantum dots (QDs) have been under extensive study as a promising material to realize the concept of the intermediate band solar cell (IBSC). Because thermal escape is the dominant mechanism of carrier escape at room temperature, wide-band-gap (WBG) semiconductor can be used to suppress thermal escape by increasing barrier height for InAs quantum dots. Embedded InAs QD in the wide-bandgap matrix (InGaP and AlGaAs) is demonstrated with increased sub-band-gap carrier collection. The deeper confinement and larger activation energy is a move towards realizing an IBSC Additionally, activation energy extracted from temperature dependent external quantum efficiency (TDEQE) of InAs/AlGaAs is 324 meV, which is closer to the transition between IB to CB in an ideal IBSC.