A numerical approach for analyzing quantum dot infrared photodetectors' parameters

Quantum dot infrared photodetectors (QDIPs) have many advantages over other types of semiconductor-based photodetectors. However some of its characteristics have been investigated theoretically, there are many unstudied points. In this paper a new approach is presented to evaluate quantum dot infrared photodetectors dark current and photocurrent. In this study, it is assumed that both thermionic emission and field-assisted tunneling mechanisms determine the dark current of quantum dot detectors. Based on these assumptions, new formula for average number of electron in a quantum dot for both, dark and illumination condition is calculated, which is more accurate than the previous reported formulas; because in deriving previous reported formulas, it was assumed only thermionic emission determines dark current but field-assisted tunneling mechanisms has not been considered. Then numerical method is used to calculate the average number of electron in a quantum dot and to determine dark current and photocurrent. The theoretical results are compared with experimental data. They have good agreement with available experimental data.

► In this work we studied the Quantum dot infrared photodetectors (QDIPs) dark current and photocurrent.
► In the study of dark current we considered both thermionic emission and field-assisted tunneling mechanisms to determine the dark current of quantum dot detectors.
► In the calculation of QDIP dark current and photocurrent it is necessary to determine the average number of electron in each quantum dot.
► We have presented simple formulas to determine this, in the dark and illumination condition.
► Based on the presented simple formulas, the dark current and photocurrent is calculated and compared with experimental data reported in the literatures.