Sequential coupling transport for the dark current of quantum dots-in-well infrared photodetectors

Abstract

The dark current characteristics and temperature dependence for quantum dot infrared photodetectors have been investigated by comparing the dark current activation energies between two samples with identical structure of the dots-in-well in nanoscale but different microscale n-i-n environments. A sequential coupling transport mechanism for the dark current between the nanoscale and the microscale processes is proposed. The dark current is determined by the additive mode of two activation energies: Ea,micro from the built-in potential in the microscale and Ea,nano related to the thermally assisted tunneling in nanoscale. The activation energies Ea,micro and Ea,nano decrease exponentially and linearly with increasing applied electric field, respectively.

Deep level centers and their role in photoconductivity transients of InGaAs/GaAs quantum dot chains

“…For example, the WL serves as a channel for carrier exchange between the QDs 6,7 and directly influences the dark current of infrared photodetectors. 8,9 For QD heterostructures grown by molecular beam epitaxy (MBE), the thicknesses of the transition regions between materials become comparable to the sizes of the nanostructures themselves. Electrical and optical properties of such heterostructures therefore become dependent on the ideality of the InGaAs/GaAs interfaces, and their description should take into account a realistic influence of the interface states as well as the quantum confined states.…”

Monte Carlo Simulation of Electrons Transport in Quantum Dot Infrared Photodetector

“…Figure 4 shows the dark current of the QDIP based on the monte carlo simulation of the electron transport. In this figure, the curve with " " represents our calculated dark current values at 130 K, the other curve including " " describes the measured dark current data at the same temperature form the QDIP device in the literature, 15 which is made up of the 10-period stack layers of 4.5 nm In 0 15 Ga 0 85 As/2.2 ML InAs quantum dot/6 nm In 0 15 Ga 0 85 As/50 nm GaAs barriers and the top contact layers, the bottom contact layer. Let us compare the two curves, we can find that the two curves have a good consistency each other within the range of the electric field density 1 kV/cm ∼20 kV/cm.…”

Dark current and noise analyses of quantum dot infrared photodetectors

“…These calculations are performed based on the parameters of the ten period QDIP device fabricated from GaAs or InGaAs [15][16][17][18][19][20], and these parameters are shown in the Table 1. Figure 1 shows the dark current as a function of the applied electric field.…”

“…This activation energy depends on the total of the microscale and the nanoscale electron transport [12,15], and it can be calculated as…”