Vertical transport in InAs/GaSb type-II strained layer superlattices for infrared focal plane array applications

Abstract

In this work, we report on the measurement of vertical transport parameters in p-doped InAs/GaSb type-II superlattices for long-wavelength infrared detectors. Variable magnetic eld geometrical magnetoresistance mea- surements have been employed to extract the vertical transport parameters, since the Hall-eect technique cannot be employed in the vertical transport conguration. The room-temperature magnetoresistance measurements were performed employing a kelvin-mode set up, at electric elds not exceeding 25 V/cm and at magnetic eld intensities up to 12 T. The measured magnetoresistance, shown to exhibit multiple-carrier conduction charac- teristics, were analyzed using a high-resolution mobility spectrum analysis technique. It is shown that, at room temperature, the electrical conductivity of the sample is due to four distinct carriers, associated with the major- ity carrier holes, sidewall inversion layer electrons, and two minority carrier electrons likely associated with two distinct conduction band levels.