High-performance, long-wave (∼10.2 μm) InGaAs/GaAs quantum dot infrared photodetector with quaternary In0.21Al0.21Ga0.58As capping

Abstract

A high-performance InGaAs/GaAs vertical quantum dot infrared photodetector (QDIP) with combined barrier of quaternary In 0.21 Al 0.21 Ga 0.58 As and GaAs was investigated in this study. A dominant long wavelength ($10.2 lm) response was observed from the device. The device demonstrates large responsivity (2.16 A/W) with narrow spectral-width (Dk/k $0.14) and high detectivity (1.01 Â 10 11 cm Hz 1/2 /W at 0.3 V) at 10.2 lm at 77 K. In addition, the device has also produced a detectivity in the order of 6.4 Â 10 10 cm Hz 1/2 /W at 100 K at a bias of 0.2 V, indicating its suitability for high-temperature operations. V

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

“…The optical and electrical properties of such heterostructures can be modulated by tuning the size, shape, and density of the QDs as well as the capping layers. Recently, QD infrared photodetectors (QDIPs) have attracted considerable attention because of their ability to provide high detectivity and responsivity, low dark current, high efficiency, and long lifetime, which are attributable to reduced electron phonon scattering [6][7][8][9]. However, such systems present a serious drawback because of the nonuniform QD distribution, growth-induced defects, and dot formation accuracy, among others.…”

Effects of high energy proton implantation on the optical and electrical properties of In(Ga)as/GaAs QD heterostructures with variations in the capping layer

“…The most common capping layers used for InAs dots are GaAs, InGaAs, GaAsSb [12], and the quaternary alloy, InAlGaAs. Although some of best results have been obtained for In(Ga)As/GaAs QDs with InAlGaAs capping [13], this method has not found extensive use. The quaternary alloy In 0.21 Al 0.21 Ga 0.58 As capping layer used for InAs QDs acts as a strain-driven, phase-separation alloy [14].…”

Effect of the interface on UV–vis–IR photodetection performance of PbS/ZnO nanocomposite photocatalysts

“…Lead sulfide (PbS) has attracted wide interest because of its narrow band gap (0.41 eV), size-dependent optical properties, and optoelectronic properties. These properties offer better carrier transport characteristics and wide spectral responses from UV to infrared region for a variety of applications such as photovoltaics, photodetection [1,5,6]. It is crucial to find strategy to improve the separation efficiency of photogenerated electrons (e) and holes (h) for the application of PbS in photovoltaics and photodetection.…”

“…However, the conventional photodetectors can only detect one specific optical spectral band, such as InGaAs for near-infrared detection, Si for visible detection, and ZnO for UV detection [1][2][3][4]. Lead sulfide (PbS) has attracted wide interest because of its narrow band gap (0.41 eV), size-dependent optical properties, and optoelectronic properties.…”