Recombination dynamics in quantum-dot infrared photodetectors with spherical and lens-shaped potential

Abstract

The recombination time for quantum dot infrared photodetectors (QDIPs) for spherical and lens-shaped potential has been compared for variations of different physical parameters such as radius of quantum dots (QDs), capture rate strength and trap concentration. The geometric shape of QDs has a very strong impact on the response of QDIPs. The effect of different shapes such as spherical and lens-shaped potential on the recombination time has been studied. The longer lifetime, i.e, higher recombination time of excited electrons leads to better response, low dark current and large detectivity. QDIPs which have longer carrier lifetimes have an advantage of higher photoconductive gain and higher operating temperatures. As recombination time directly affects the gain of the device, this parameter has been treated with utmost importance.