Device model for quantum dot infrared photodetectors and their dark-current characteristics

Abstract

We propose a device model for quantum dot infrared photodetectors (QDIPs) with relatively large lateral spacing between QDs as occurs in QDIPs fabricated and experimentally investigated recently. The developed model accounts for the self-consistent potential distribution and features of the electron capture and transport in realistic QDIPs in dark conditions. The model is used for the calculation of the dark current as a function of the structural parameters, applied voltage and temperature. It explains a rather sharp increase in the dark current with increasing applied voltage and its strong sensitivity to the density of QDs and the doping level of the active region. The calculated dependences are in good agreement with available experimental data. The obtained characteristics of QDIPs are compared to those of QWIPs with similar parameters.

Block Diagram Programming of Quantum Dot Sources and Infrared Photodetectors for Gamma Radiation Detection Through VisSim

“…In this subsection, different treatments are applied to model the characteristics of QDIPs than that in [16][17] under gamma radiation. Furthermore, we will utilize a new block diagram model to consider the characteristics of a QDIP under dark and illumination condition.…”

“…In this case, the distribution of the electric potential φ=φ(x,y,z) in the active region is governed by the Poisson equation [16]       Moreover, block diagram model that describes the relation between dark current and structural parameters is implemented through VisSim as depicted in Fig. 3.2.…”

Injector Quantum Dot Molecule Infrared Photodetector: A Concept for Efficient Carrier Injection

“…In a first order approximation thermionic emission rate from a QD is proportional to exp[−ε QD /k B T ], where ε QD denotes the ground state ionization energy, k B the Boltzmann constant and T the temperature in Kelvin [12]. The electron capture by LO-phonon emission is on the other hand limited by the discrete spectrum of the QDs, i.e.…”

Comparison studies of infrared photodetectors with a quantum-dot and a quantum-wire base

“…(10) we get an equation for the potential of the first QD array. The average photocurrent density of QDIP is given by [15], [17], and [18] …”

“…Because the electron transport across the active re− gion under the effect of sufficiently strong electric field is associated with the drift, the balance equation can be pre− sented in a form much like that for QWIPs [15] …”