Quantum Dot Infrared Photodetectors

Barve, Ajit V.; Krishna, S.

doi:10.1016/b978-0-12-381337-4.00003-6

Cited by 25 publications

(30 citation statements)

References 146 publications

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“…A redshift of almost 1 lm was observed for quaternary-capped QDIPs compared with ternary-capped QDIPs. We believe the longer-excited wavelength in quaternary-capped structure is due to bound to bound state transition and for ternary capping due to bound to quasibound state as it is reported that \20 % spectral line width corresponds to bound to bound state transition and for 30-45 % bound to quasi-bound (wetting) state [25]. The measured responsivity values for Q 1 , Q2, T1, and T 2 devices were 3.37, 3.17, 1.6, and 1.23 mA/W, respectively.…”

Section: Resultsmentioning

confidence: 93%

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

et al. 2014

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We investigate and compare the performance of 30 layers strain-coupled quantum dot (SCQD) infrared photodetectors capped with one of two different layers: a quaternary (In 0.21 Al 0.21 Ga 0.58 As) or ternary (In 0.15 Ga 0.85 As) alloy of 30 Å and a GaAs layer with a thickness of 120-150 Å . Measurements of optical properties, spectral responsivity, and cross-sectional transmission electron microscopy were conducted. Results showed that quaternary capping yielded more superior multilayer QD infrared photodetectors than ternary capping. Quaternary capping resulted in enhanced dot size, order, and uniformity of the QD array. The presence of Al in the capped layer helped in the reduction in dark current density and spectral linewidth as well as led to higher electron confinement of the QDs and enhanced device detectivity. The vertically ordered SCQD system with quaternary capping exhibited higher peak detectivity (*10 10 cm Hz 1/2 /W) than that with ternary capping (*10 7 cm Hz 1/2 /W). In addition, a very low noise current density of *10 -16 A/cm 2 Hz 1/2 at 77 K was achieved with quaternary-capped QDs.

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Section: Resultsmentioning

confidence: 93%

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

et al. 2014

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“…3,4 Extensive experimental and theoretical studies have been performed on InAs QDs within GaAs matrix. More recently, QDIP structures have been implemented by covering the self-assembled InAs/GaAs QDs with a strain-relieving InGaAs cap layer.…”

Section: Introductionmentioning

confidence: 99%

“…More recently, QDIP structures have been implemented by covering the self-assembled InAs/GaAs QDs with a strain-relieving InGaAs cap layer. 4 This dots-ina-well (DWELL) photodetector design is then based on intraband optical transitions between QD and quantum well (QW) bound-states and, hence, offers the additional possibility of engineering the detection peak wavelength by adjusting QW width and/or composition. Moreover, such QDIP schemes allow a bias-tunable spectrally adaptive response.…”

Section: Introductionmentioning

confidence: 99%

Temperature-dependent modulated reflectance of InAs/InGaAs/GaAs quantum dots-in-a-well infrared photodetectors

Nedzinskas

Čechavičius

Rimkus

et al. 2015

Journal of Applied Physics

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We present a photoreflectance (PR) study of multi-layer InAs quantum dot (QD) photodetector structures, incorporating InGaAs overgrown layers and positioned asymmetrically within GaAs/AlAs quantum wells (QWs). The influence of the back-surface reflections on the QD PR spectra is explained and a temperature-dependent photomodulation mechanism is discussed. The optical interband transitions originating from the QD/QW ground-and excited-states are revealed and their temperature behaviour in the range of 3-300 K is established. In particular, we estimated the activation energy ($320 meV) of exciton thermal escape from QD to QW bound-states at high temperatures. Furthermore, from the obtained Varshni parameters, a strain-driven partial decomposition of the InGaAs cap layer is determined. V C 2015 AIP Publishing LLC.

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“…In particular, InAs-GaAs quantum dots (QDs) have been used for QD infrared photodetectors (QDIPs), exploiting intraband electronic transitions between bound-state of QD and continuum. In recent years, an advanced InAs-InGaAs dots-in-a-well (DWELL) quantum heterostructure was implemented, where InAs QDs are covered by InGaAs strainrelieving layer (SRL), forming a quantum well (QW) [2]. This new QDIP concept is then based on intraband optical transitions between bound-states of QD and QW, thus allowing a spectrally adaptive optical response through adjusting QD/QW parameters and/or applying a bias voltage.…”

mentioning

confidence: 99%

“…1.55 µm wavelength) [1] and photodetectors (3-5 µm, [8][9][10][11][12] µm) [2]. In particular, InAs-GaAs quantum dots (QDs) have been used for QD infrared photodetectors (QDIPs), exploiting intraband electronic transitions between bound-state of QD and continuum.…”

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confidence: 99%

Temperature-dependent modulated reflectance and photoluminescence of InAs–GaAs and InAs–InGaAs–GaAs quantum dot heterostructures

et al. 2016

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Optical transitions and electronic properties of epitaxial InAs quantum dots (QDs) grown with and without InGaAs strain-relieving capping layer within GaAs/AlAs quantum well (QW) are investigated. Modulated reflectance and photoluminescence (PL) spectroscopy is used to probe the QD-and QW-related interband optical transitions over the temperature range of 3-300 K. The observed spectral features in QDs are identified using numerical calculations in a framework of 8-band k · p method. It is found that covering the dots by a 5 nm-thick InGaAs layer yields the energy red-shift of ground-state transition by ∼ 150 meV. Moreover, the analysis of interband transition energy dependence on temperature using Varshni expression shows that material composition of InAs QDs significantly changes due to Ga/In interdiffusion. A comparison of emission-and absorption-type spectroscopy applied for InAs-GaAs QDs indicates a Stokes shift of ∼ 0.02 meV above 150 K temperature.

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Quantum Dot Infrared Photodetectors

Cited by 25 publications

References 146 publications

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

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

Temperature-dependent modulated reflectance of InAs/InGaAs/GaAs quantum dots-in-a-well infrared photodetectors

Temperature-dependent modulated reflectance and photoluminescence of InAs–GaAs and InAs–InGaAs–GaAs quantum dot heterostructures

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