Impact of quantum dot parameters on the performance of p-type quantum dot infrared photodetectors

Abstract

In this work, the impact of the quantum dot parameters, including dot size, and material composition on the optoelectronic performance of quantum dot infrared photodetectors (QDIPs) is systematically studied. The QDIP is based on the intra-valence band transitions in Zn 1-x Cd x Se QDs. The eigen energies and wavefunction of the hole states are computed under the framework of the multi-band k.p model. The obtained electronic structure is further utilized to calculate the dark current density, responsivity, and detectivity of QDIPs. An increase in CdSe content markedly reduces the dark current density as well as improves the responsivity. As a result, detectivity enhances significantly. Raising the QD size also brings enhancement in the detectivity. Moreover, peak response wavelength depends on the CdSe content and dot dimensions. These results might provide new directions for the development of p-type II-VI QDs based QDIP. • Infrared photodiode based on the intervalence band absorption has been studied. • Strain dependent multiband effective mass k.p model is used to compute the electronic structure of QDs. • Higher CdSe content and larger quantum dot yields better optoelectronic performance. • The Peak response wavelength is quite sensitive to the CdSe content.