Effects of Si doping on normal incidence InAs∕In0.15Ga0.85As dots-in-well quantum dot infrared photodetectors

Abstract

Resonant cavity enhanced In As ∕ In 0.15 Ga 0.85 As dots-in-a-well quantum dot infrared photodetector InAs quantum dot infrared photodetectors with In 0.15 Ga 0.85 As strain-relief cap layersThe effects of doping on InAs/ In 0.15 Ga 0.85 As quantum dots-in-well infrared photodetectors have been studied by measuring the dark current, photocurrent, and spectral response. A significant reduction of dark current with decrease in doping concentration in the quantum dots has been observed. However, the photocurrent of the detectors increases with the doping. By measuring the background limited infrared photodetector temperature, we find that the optimum sheet doping concentration in these detectors is n =3ϫ 10 10 cm −2 ͑corresponding to about one electron per dot͒.

Optical pumping as artificial doping in quantum dots-in-a-well infrared photodetectors

“…As an alternative to fabricating many samples with different doping concentrations, 13 we employed resonant interband excitation to tune the population in a specific QD energy state. A major increase in the height of the 148 meV peak was observed during excitation resonant with the QD ground state ͑at 1165 meV͒, accompanied by a minor increase in the 120 meV peak height ͓Fig.…”

A monolithically integrated plasmonic infrared quantum dot camera

“…The growth rates, substrate temperatures and the flux ratios were previously optimized 26 for maximizing the photoluminescence intensity from the quantum dots. Quantum dots were n-doped with Si with approximately two electrons per dot, for optimizing 27 the detector performance. The thickness and compositions of In 0.15 Ga 0.85 As and Al 0.08 Ga 0.92 As layers were selected to achieve 1) resonances, the response of the sP-FPA is brighter than that of the non-sP-FPA, whereas the effect is reversed off resonance.…”

Broadband photoresponse from InAs quantum dots embedded in a graded well for visible to mid-infrared detection

“…For non-equilibrium measurements, QDs are populated by the charge carriers that are generated from the contact layers and swept under the influence of a bias voltage. To date, mid-infrared (MIR) detection based on intersubband transition in InAs QDs, InAs dots-in-a-well and InGaAs QDs ranging between 2 and 20 µm have been reported for various operation temperatures [5][6][7][8] . In this study, visible to MIR (0.4 -20 µm) photoresponse from interband and intersubband transitions in InAs dots-in-a-graded-well (DGWell) is presented.…”