A microscopic model of electron transport in quantum dot infrared photodetectors

Abstract

A theoretical model describing the electron transport in vertical conductivity quantum dot infrared photodetectors is presented. The carrier wave functions and energy levels were evaluated using the strain dependent eight-band k∙p Hamiltonian and used to calculate all intra- and interperiod transition rates due to interaction with phonons and electromagnetic radiation. The interaction with longitudinal acoustic phonons and electromagnetic radiation was treated perturbatively within the framework of Fermi’s golden rule, while the interaction with longitudinal optical phonons was considered taking into account their strong coupling to electrons. A system of rate equations was then formed, from which the macroscopic device output parameters such as dark current and responsivity, as well as microscopic information about carrier distribution in quantum dots and continuum states, could be extracted. The model has been applied to simulate the dark current, as well as the midinfrared photoresponse in an experimentally realized device [Chen et al., J. Appl. Phys. 89, 4558 (2001)], and a good agreement with experiment has been obtained. Being free from any fitting or phenomenological parameters, the model should be a useful tool in the design and prediction of the characteristics of the existing or other types of quantum dot infrared photodetectors.

Theoretical study of intraband optical transitions in conduction band of dot-in-a-well system

“…Other properties of DWELL photodetectors, such as generation of the photocurrent, the bias dependence of the photoresponse, and variation of the composition of DWELL system, were also studied both theoretically and experimentally. [35][36][37][38][39] In the present paper the conduction band mass of In 0.15 Ga 0.85 As, InAs and GaAs were taken from Ref. 40.…”

Carrier transport in multilayer InAs/GaAs quantum dot heterostructures grown by ion beam crystallization

“…To find ways of raising the operating temperature of QDIPs, a number of researchers investigated carrier transport in them. Vukmirovic et al [7] reached good agreement between their theoretical results and experimental data only at 77 K and electric fields within 25 kV/cm. Naser et al [8] failed to achieve appropriate accuracy at temperatures below 80 K and bias voltages under 0.5 V. A model proposed by Ryzhii et al [9] is based on thermionic emission from QDs and works well only above 10 K. Stiff Roberts et al [10] included a field assisted tunneling emission mechanism in that model, which allowed them to improve agreement at high bias voltages and high temperatures.…”

Colloidal and Epitaxial Quantum Dot Infrared Photodetectors: Growth, Performance, and Comparison

“…It determines the maximum operating temperature of the detector for a given signal-to-noise ratio (SNR). Detailed modeling of dark current and transport in QDIPs already has been investigated (57,(117)(118)(119). The dark current density in a QDIP is given by…”