| Summary: | 碩士 === 元智大學 === 電機工程學系丙組 === 107 === This study investigated the effects of indium gallium arsenide (InGaAs) quantum dots (QDs) covering aluminum gallium arsenide antimony (AlGaAsSb) on the optoelectronic properties of the future solar cells. Since the QD emission wavelength is positively correlated with the indium-containing composition of the quantum dot structure, the carrier limitation, and the internal compressive stress, the shorter emission wavelength indicates the lower material structural stress and the epitaxial defects that may occur, and the preferred material. quality. In order to avoid quantum dot defects caused by excessive stress, the preparation of optimal luminescent wavelength quantum dots has a considerable influence on the efficiency of future quantum dot solar cell devices. This research direction is based on the study of 6.6ML InGaAs quantum dots. For the further structural design of the capping layer, the difference of the presence or absence of aluminum between the antimony-containing aluminum capping layer and the antimony-containing capping layer is compared.The quantum dots with the AlGaAsSb capping layer have a distinct first excited state, and the quantum dot photoluminescence intensity is significantly better than that of the antimony-containing cladding layer (2 nm GaAsSb). The possible reason is that the aluminum-containing cladding layer can improve the carrier confinement of the QD structure, so the PL luminous intensity of QD can be increased. In addition, the aluminum-containing structure can reduce the In-Ga intermixing phenomenon between the quantum dots and the capping layer, so that the longer wavelength of the emission is extended to 1210 nm, and the quantum carrier has a special carrier limitation, and the first excitation can be exhibited by the spectrum. This quantum dot structure of good optical properties is expected to increase the open circuit voltage of aluminum-containing quantum dot solar cell devices and their overall device conversion efficiency.
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