Insight into performance of quantum dot infrared photodetectors

Abstract. In the paper, an algorithm for theoretical evaluation of dark and illumination characteristics of quantum dot infrared photodetectors (QDIPs) is presented. The developed algorithm is based on a model previously published by Ryzhii and co-workers. In our considerations it is assumed that both thermionic emission and field-assisted tunnelling mechanisms determine the dark current of quantum dot detectors. The model permits to calculate the dark current, current gain, average number of electrons in quantum dots, photocurrent, and detector responsivity as a function of the structural parameters. Moreover, it explains some features of QDIP characteristics. In several cases, the theoretical predictions are compared with experimental data. Good agreement between both kinds of data has been obtained. Key words: QDIPs, dark current, current gain, responsivity, detectivity