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Sanjay Krishna Co-authored Publication in Applied Physics Letters

Sanjay Krishna was a co-author on a recent Applied Physics Letter publication. Lilian Casias, the primary author of the paper, is a KIND alum.The paper, Vertical carrier transport in strain-balanced InAs/InAsSb type-II superlattice material, can be read below.


Anisotropic carrier transport properties of unintentionally-doped InAs/InAs0.65Sb0.35 type-II strain-balanced superlattice material are evaluated using temperature- and field-dependent magnetotransport measurements performed in the vertical direction on a substrate-removed metal-semiconductor-metal device structure. To best isolate the measured transport to the superlattice, the device fabrication entails flip-chip bonding and backside device processing to remove the substrate material and deposit contact metal directly to the bottom of an etched mesa. High-resolution mobility spectrum analysis is used to calculate the conductance contribution and corrected mixed vertical-lateral mobility of the two carrier species present. Combining the latter with lateral mobility results from in-plane magnetotransport measurements on identical superlattice material allows for calculation of the true vertical majority electron and minority hole mobilities; an amplitude of 4.7 ×103 cm2/Vs and 1.60 cm2/Vs, respectively, are determined at 77 K. Temperaturedependent results indicate vertical hole mobility rapidly decreases with decreasing temperature due to trap-induced localization and then hopping transport, whereas vertical electron mobility appears phonon scattering-limited at high temperature giving way to interface roughness scattering at low temperatures, analogous to the lateral electron mobility but with a lower overall magnitude.