Time-resolved, nonequilibrium carrier and coherent acoustic phonon dynamics in (Cd, Mg)Te single crystals for radiation detectors

Serafini, John; Hossain, Anwar; James, R. B.; Trivedi, Sudhir; Sobolewski, Roman

doi:10.1088/1361-6641/ab0219

Cited by 3 publications

(1 citation statement)

References 37 publications

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“…The normalized differential reflectivity ∆R/R for a Cd0.97Mg0.03Te crystal is presented in Figure5(b). The ∆R/R signal has the 150-fs rise time limited only by how fast the energy of the pump pulse is absorbed by the sample (integral of a 100-fs optical pulse), while the fall time can be extremely well fitted by the Drude model and shows a single-exponential relaxation dependence:17 ∆R/R ∝ exp(−t/τ)…”

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confidence: 99%

Picosecond (Cd,Mg)Te detectors for both optical and x-ray photons

Cheng

Komissarov

Chakraborty

et al. 2023

Quantum Optics and Photon Counting 2023

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We present a photodetector capable of detecting both optical and x-ray picosecond pulses, based on our in-house grown cadmium magnesium telluride (Cd,Mg)Te single crystals. We focused on a specific Cd0.97Mg0.03Te, In-doped crystal composition, because of its bandgap suitable for 800-nm-wavelength light detection and a single-picosecond optical photoresponse. The detector was fabricated as a planar metal-semiconductor-metal structure with interdigitated electrodes and exhibited a linear, Schottky-free, current-voltage characteristics with <40-pA dark current and up to 20-mA/W responsivity. The detector temporal resolution was measured to be ~200 ps full-width-at-half-maximum transient, in response of ~100-fs-wide pulses consisting of either optical (800 nm wavelength) or X-ray (4.5 keV) photons and was limited by the detector housing and 15-GHz bandwidth of the readout oscilloscope. The latter demonstrates the detector is suitable for coarse timing in X-ray free-electron laser/optical femtosecond pump-probe spectroscopy applications. We also demonstrated that due to its very high stopping power, the Cd0.97Mg0.03Te detector responded well to various nuclear gamma sources with energy ranging from 59.6 keV to 660 keV.

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confidence: 99%

Picosecond (Cd,Mg)Te detectors for both optical and x-ray photons

Cheng

Komissarov

Chakraborty

et al. 2023

Quantum Optics and Photon Counting 2023

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(Cd,Mg)Te crystals for picosecond-response optical-to-x-ray radiation detectors

Cheng

Chen

Chakraborty

et al. 2022

Review of Scientific Instruments

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We demonstrate a photodetector sensitive to both optical and x-ray picosecond pulses based on our in-house grown cadmium magnesium telluride (Cd,Mg)Te single crystal. Specifically, we developed In-doped Cd0.96Mg0.04Te material and discuss its femtosecond optical photoresponse, as well as the detector performance, such as <100-pA dark current and up to 0.22-mA/W responsivity for 780-nm wavelength optical radiation. The detector exposed to Ti fluorescence (K alpha) x-ray pulses at 4.5 keV, generated by a free-electron laser beam with the central energy of 9.8 keV and <100 fs pulse width, exhibited readout-electronics-limited 200-ps full-width-at-half-maximum photoresponse, demonstrating that it is suitable for coarse timing in free-electron laser x-ray/optical femtosecond pump–probe spectroscopy applications.

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