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arXiv · 1511.00042

Suppression of phonon-mediated hot carrier relaxation in type-II InAs/AlAs$_{x}$Sb$_{1-x}$ quantum wells: a practical route to hot carrier solar cells

H. Esmaielpour·V. R. Whiteside·J. Tang·S. Vijeyaragunathan·T. D. Mishima·S. Cairns·M. B. Santos·B. Wang·I. R. Sellers
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Abstract

InAs/AlAs$_{x}$Sb$_{1-x}$ quantum wells are investigated for their potential as hot carrier solar cells. Continuous wave power and temperature dependent photoluminescence indicate a transition in the dominant hot carrier relaxation process from conventional phonon-mediated carrier relaxation below 90 K to a regime where inhibited radiative recombination dominates the hot carrier relaxation at elevated temperatures. At temperatures below 90 K photoluminescence measurements are consistent with type-I quantum wells that exhibit hole localization associated with alloy/interface fluctuations. At elevated temperatures hole delocalization reveals the true type-II band alignment; where it is observed that inhibited radiative recombination due to the spatial separation of the charge carriers dominates hot carrier relaxation. This decoupling of phonon-mediated relaxation results in robust hot carriers at higher temperatures even at lower excitation powers. These results indicate type-II quantum wells offer potential as practical hot carrier systems.

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H. Esmaielpour, V. R. Whiteside, J. Tang, S. Vijeyaragunathan, T. D. Mishima, S. Cairns, M. B. Santos, B. Wang, I. R. Sellers. 2015-10-30. Suppression of phonon-mediated hot carrier relaxation in type-II InAs/AlAs$_{x}$Sb$_{1-x}$ quantum wells: a practical route to hot carrier solar cells. https://doi.org/10.1002/pip.2763

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