Experimental observation of transient photocurrent overshoot in quantum well infrared photodetectors

Letov, V.; Perera, A. G. U.; Ershov, M.; Liu, H.C; Buchanan, M.; Wasilewski, Z. R.

doi:10.1016/s1350-4495(01)00082-2

Cited by 6 publications

(5 citation statements)

References 10 publications

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“…2c; Supplementary Section 7). A photocurrent overshoot 30,31 in the on/off switching is observed for illumination on or near the graphene (0 ≤ X < 10 µm) with a high laser power (Supplementary Section 7). We found that both the photocurrent and photoresponsivity do not change significantly up to distances of ∼100 µm, and then they decrease by more than one order of magnitude with increasing distance (Fig.…”

Section: Position-sensitive Nonlocal Large-area Photoresponsementioning

confidence: 99%

Position-dependent and millimetre-range photodetection in phototransistors with micrometre-scale graphene on SiC

et al. 2017

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The extraordinary optical and electronic properties of graphene make it a promising component of high-performance photodetectors. However, in typical graphene-based photodetectors demonstrated to date, the photoresponse only comes from specific locations near graphene over an area much smaller than the device size. For many optoelectronic device applications, it is desirable to obtain the photoresponse and positional sensitivity over a much larger area. Here, we report the spatial dependence of the photoresponse in backgated graphene field-effect transistors (GFET) on silicon carbide (SiC) substrates by scanning a focused laser beam across the GFET. The GFET shows a nonlocal photoresponse even when the SiC substrate is illuminated at distances greater than 500 µm from the graphene. The photoresponsivity and photocurrent can be varied by more than one order of magnitude depending on the illumination position. Our observations are explained with a numerical model based on charge transport of photoexcited carriers in the substrate.

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Section: Position-sensitive Nonlocal Large-area Photoresponsementioning

confidence: 99%

Position-dependent and millimetre-range photodetection in phototransistors with micrometre-scale graphene on SiC

et al. 2017

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“…It has been shown recently that also the frequency dependent behavior of the responsivity is affected by the recharging process. 12,13 At low operation temperatures or at short detection wavelengths ͑e.g., 3-5 m͒ the differential conductivity is much smaller than for the QWIP investigated in the present study, such that the cutoff frequency of the recharging process can be substantially smaller than the 50 Hz measurement bandwidth of a typical QWIP IR-camera.…”

mentioning

confidence: 99%

Influence of the recharging process on the dark current noise in quantum-well infrared photodetectors

Rehm

Schneider

Walther

et al. 2002

Applied Physics Letters

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We show that the dark current noise spectrum of an In(0.30)Ga(0.70)As/GaAs quantum-well infrared photodetector (QWIP) is characterized by two plateau-like frequency regions. At high frequencies, the observed noise current is due to the generation-recombination noise of carriers, which have been emitted thermionically from the quantum wells into the continuum. In the low-frequency regime, an additional contribution to the noise current is caused by the redistribution of space charges, that occurs on a time scale similar to the dielectric relaxation time

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“…The small overshoot in the rise time in the photoresponse measured under 800 and 850 nm excitation has previously been attributed to space–charge effects in mid‐IR quantum‐well detectors. [ 33 ] A similar effect can occur in our p‐B‐n photodiode, where the fast photoinjection of carriers may cause a nonlinear response of the built‐in field at the CdTe/Cd 3 As 2 interface. The response times are similar to that of a commercial InGaAs detector, shown in Figure 3g for comparison.…”

Section: Resultsmentioning

confidence: 65%

Epitaxial Dirac Semimetal Vertical Heterostructures for Advanced Device Architectures

Rice

Lee

Fluegel

et al. 2022

Adv Funct Materials

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Exploiting the extraordinary transport and optical properties of 3D topological semimetals for device applications requires epitaxial integration with semiconductors to carefully control carrier transport, yet no studies have established heteroepitaxy on top of any topological semimetals to date. Here, a novel approach toward fabricating heterostructures is demonstrated by epitaxially incorporating the Dirac semimetal Cd 3 As 2 between Zn x Cd 1-x Te and CdTe layers via molecular beam epitaxy on GaAs (001) substrates. The approach utilizes the higher energy (001) surface of Cd 3 As 2 to stabilize 2D epitaxy of zinc blende semiconductors. To demonstrate the impact heterostructure formation offers to device performance, an all-epitaxial, barrier-type vertical photodetector is fabricated that accesses a different carrier separation mechanism than previously reported non-epitaxial junctions and consequently exhibits significantly reduced dark currents. The results highlight the important role that epitaxial integration can play in accessing advanced architectures for topological semimetal-based devices.

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Experimental observation of transient photocurrent overshoot in quantum well infrared photodetectors

Cited by 6 publications

References 10 publications

Position-dependent and millimetre-range photodetection in phototransistors with micrometre-scale graphene on SiC

Position-dependent and millimetre-range photodetection in phototransistors with micrometre-scale graphene on SiC

Influence of the recharging process on the dark current noise in quantum-well infrared photodetectors

Epitaxial Dirac Semimetal Vertical Heterostructures for Advanced Device Architectures

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