A multicolor, broadband (5–20 μm), quaternary-capped InAs/GaAs quantum dot infrared photodetector

Abstract

An InAs/GaAs quantum dot infrared photodetector with strong, multicolor, broadband (5-20 lm) photoresponse is reported. Using a combined quaternary In 0.21 Al 0.21 Ga 0.58 As and GaAs capping that relieves strain and maintains strong carrier confinement, we demonstrate a four color infrared response with peaks in the midwave-(5.7 lm), longwave-(9.0 and 14.5 lm), and far-(17 lm) infrared regions. Narrow spectral widths (7% to 9%) are noted at each of these wavelengths including responsivity value $95.3 mA/W at 14.5 lm. Using strain field and multi-band k Á p theory, we map specific bound-to-bound and bound-to-quasibound transitions to the longwave and midwave responses, respectively. V

Ultra‐Broadband Photodetector for the Visible to Terahertz Range by Self‐Assembling Reduced Graphene Oxide‐Silicon Nanowire Array Heterojunctions

“…High‐performance broadband photodetectors have recently attracted significant interest because of their importance to a variety of applications, including imaging, remote sensing, environmental monitoring, astronomical detection, photometers and analytical applications. Graphene is a promising material for broadband photodetection applications because of its ability to absorb incident light over a wide wavelength range, from at least the visible (VIS) spectrum to the infrared .…”

Enhancement of device performance by using quaternary capping over ternary capping in strain-coupled InAs/GaAs quantum dot infrared photodetectors

“…By appropriate modulation of the growth parameters, control of the shape, size, density of the dots in the seed layer, and precise adjustment of the thickness of the spacer layer between the seed and active layers, we can minimize the size non-uniformity of the dots in the active layer. However, it is believed that the benefit of using quaternary capping with a specific alloy composition can provide strong carrier confinement, which simultaneously results in strain relief in the QD layer, thereby realizing high-quality QDs [15]. The dot strain and mismatch between InAs dots and the quaternary-capped layer reduce the defect and minimize lattice vibration, which provides high detector response.…”

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Self-Assembly in Semiconductor Epitaxy

“…Large QDIP focal plane arrays [224] operating in the range of thermoelectric coolers and four-color operation [225] have been demonstrated. Large QDIP focal plane arrays [224] operating in the range of thermoelectric coolers and four-color operation [225] have been demonstrated.…”