Radiative recombination in narrow gap HgTe/CdHgTe quantum well heterostructures for laser applications

Abstract

Recent progress in the molecular beam epitaxy (MBE) of CdHgTe/HgTe quantum well (QW) heterostructures paves the way to a new generation of photodetectors, light-emitting diodes and lasers [1,2]. A remarkable feature of such structures is the ability to suppress the Auger recombination in narrow (<10 nm) QWs in contrast to bulk-like wells [3]. In conjunction with a variable bandgap (from 0 to 1.5 eV), this feature allows developing long-wavelength lasers on interband transitions. Such lasers could be of use in 3.5-4.5 µm and 8-13.5 µm wavelength bands, corresponding to the atmospheric transparency windows, as well as in 25-50 µm range, where no quantum cascade lasers (QCLs) are available as yet. Coherent radiation from a HgCdTe (MCT) bulk alloy was first obtained in 1966 [4], 4 years after the very first semiconductor laser had appeared [5]. Interest in stimulated emission (SE) from MCT was revived in the 1990s [6,7], when the MCT growth technology was developing rapidly for the mid-infrared (IR) detectors [8]. However, this interest faded quickly, most likely due to the fast progress of mid-IR QCLs, happening about the same time. By 2015, the longest wavelength of coherent radiation obtained from MCT was 5.3 µm [6]. In recent years, some progress has been made as far as coherent radiation from MCT material is concerned [9][10][11]: in particular, SE up to ~20 µm has been demonstrated in [9]. The possibility of optical gain in HgCdTe QWs in 20-60 µm range has been already theoretically predicted [12]. However, for the development of lasers and photodetectors, scrutiny of carrier recombination is of paramount importance. CdHgTe/HgTe QW structures were poorly studied in this respect, especially as far as narrow-gap QWs are

Carrier Recombination, Long‐Wavelength Photoluminescence, and Stimulated Emission in HgCdTe Quantum Well Heterostructures

“…Experimental curves in Figure (a and b) are accompanied with the theoretical curve of carrier density dynamics calculated for the case when only radiative recombination is taken into account. The calculation was performed using the Kane 8 × 8 model and is discussed in detail elsewhere . In this work, we compare the results of the calculation with the experimental PC kinetics for the structures under study.…”

Optical Studies and Transmission Electron Microscopy of HgCdTe Quantum Well Heterostructures for Very Long Wavelength Lasers

“…As was shown earlier for structures analogous to str. #A0120 [ 35 ], in str. #A0120, the recombination is controlled by the radiative process.…”

“…The model used to calculate the radiative recombination lifetimes is described in Ref. [ 35 ]. The threshold energies of Auger recombination were estimated numerically using the extremum search method as described in Ref [ 36 ].…”

Влияние ростовой температуры на пассивирующие свойства пленок Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-, выращенных методом атомно-слоевого осаждения на поверхности CdHgTe

“…Тройное соединение кадмий−ртуть−теллур (КРТ) активно применяется для создания фотоприемных устройств в инфракрасной области спектра, изучения топологических изоляторов, лазеров в инфракрасной области спектра и создания структур с двумерным электронным газом [1][2][3]. Важной задачей при создании устройств на основе КРТ является выбор пассивирующего покрытия.…”

“…В дальнейшем пластина отжигалась при минимальном давлении паров ртути для перевода пленки КРТ в вакансионный p-тип проводимости. Концентрация дырок и их подвижность после отжига были измерены методом Холла и составили 9.5 • 10 15 cm −3 и 370 cm 2 • можно охарактеризовать по разнице напряжений плоских зон в прямом и обратном направлениях ( U f b ) (по гистерезису ВФХ [14]). В таблице приведены значения U f b для интервала напряжений от −3 до +3 V. Исходя из величины минимальной емкости можно определить концентрацию акцепторов в приповерхностной области [15].…”