В двух волноводных гетероструктурах с массивами квантовых ям Hg0.892Cd0.108Te/Cd0.63Hg0.37Te толщиной 6.1 нм и Hg0.895Cd0.105Te/Cd0.66Hg0.34Te толщиной 7.4 нм при 8 K впервые получено стимулированное излучение на длинах волн 10.3 и 14 мкм при непрерывном оптическом возбуждении. Показано, что благодаря наличию Cd в квантовых ямах уменьшается влияние флуктуаций толщины квантовых ям на энергию межзонных переходов в ней, что в итоге может являться причиной существенного уменьшения пороговой интенсивности для генерации стимулированного излучения. Ключевые слова: HgCdTe, квантовые ямы, стимулированное излучение, непрерывная генерация.

Wavefunctions of electron have been calculated for conduction band of zero-gap HgCdTe alloy with Coulomb acceptor. Energies of resonant states have been estimated.

В гетероструктурах с квантовыми ямами Hg(Cd)Te/CdHgTe в области длин волн 3-4 мкм выполнены исследования стимулированного излучения на межзонных переходах в зависимости от длины волны накачки. Минимальное значение пороговой плотности мощности и максимальная температура, при которых удается получить стимулированное излучение, соответствуют энергиям кванта накачки вблизи ширины запрещенной зоны барьеров. В структуре с толщиной покровного слоя 150 нм при непрерывной накачке и температурах выше 200 K было обнаружено структурное уширение спектра излучения, связываемое с проявлением эффекта Штарка, возникающего из-за влияния электрического поля области пространственного заряда поверхностного барьера. Ключевые слова: кадмий--ртуть--теллур, стимулированное излучение, окно прозрачности атмосферы, эффект Штарка.

In two waveguide heterostructures with quantum-well arrays of Hg0.892Cd0.108Te/Cd0.63Hg0.37Te with a thickness of 6.1 nm and Hg0.895Cd0.105Te/Cd0.66Hg0.34Te with a thickness of 7.4 nm, stimulated emission is first obtained at wavelengths of 10.3 and 14 μm under continuous optical excitation at 8 K. It is shown that, due to the presence of Cd in the quantum wells, the effect of fluctuations in the thickness of the quantum wells on the energy of interband transitions in it decreases, which can ultimately cause a significant decrease in the threshold intensity for stimulated emission.

The terahertz photoluminescence spectra of HgTe/CdHgTe heterostructure with quantum wells under interband optical excitation with a power of 3 to 300 mW have been studied in the temperature range of 30–100 K. The photoluminescence spectrum includes a band corresponding to quantum energies below the width of the band gap. The position of this band does not change with increasing temperature. This property allows attributing it to the capture of holes by acceptor centers. It has been shown that these acceptor centers are singly ionized mercury vacancies, which are double acceptors. A nonmonotonic dependence of the intensity of a signal of a long-wavelength photoluminescence band on the power of an exciting source has been revealed. A short-wavelength photoluminescence band corresponding to interband transitions appears with an increase in the exciting power. It has been shown that this effect is caused by the saturation of the number of partially ionized mercury vacancies with increasing pump intensity.

Stimulated emission from a heterostructure with Hg0.903Cd0.097Te/Cd0.7Hg0.3Te quantum wells, placed in a waveguide layer of wide-gap CdHgTe, is obtained at wavelengths of 14–11 μm and a temperatures of 18–80 K. The threshold Auger recombination energy is calculated for a set of heterostructures with quantum wells of pure HgTe with a band gap of 90 meV (wavelength 14 μm). The possibility of fabricating lasers operating at 14 μm and working temperatures higher than that of liquid nitrogen is demonstrated.

AbstractStimulated emission from a heterostructure with Hg_0 . 903Cd_0 . 097Te/Cd_0 . 7Hg_0 . 3Te quantum wells, placed in a waveguide layer of wide-gap CdHgTe, is obtained at wavelengths of 14–11 μm and a temperatures of 18–80 K. The threshold Auger recombination energy is calculated for a set of heterostructures with quantum wells of pure HgTe with a band gap of 90 meV (wavelength 14 μm). The possibility of fabricating lasers operating at 14 μm and working temperatures higher than that of liquid nitrogen is demonstrated.

AbstractWe report on the stimulated emission obtained in the wavelength range of 20.3–17.4 μm on the interband transitions at T = 8–50 K in HgCdTe quantum wells placed in a dielectric waveguide formed from wide-gap CdHgTe solid solution. Heterostructures with HgCdTe quantum wells are interesting for designing long-wavelength lasers operating in the wavelength range of 25–60 μm, which is not covered by currently available quantum cascade lasers. It is shown that the maximum temperature of stimulated emission is determined by the position of lateral maxima in the dispersion dependences in the first valence subband of the quantum well. Methods for suppressing nonradiative recombination in the structures with HgCdTe quantum wells are discussed.

We report on the stimulated emission obtained in the wavelength range of 20.3–17.4 μm on the interband transitions at T = 8–50 K in HgCdTe quantum wells placed in a dielectric waveguide formed from wide-gap CdHgTe solid solution. Heterostructures with HgCdTe quantum wells are interesting for designing long-wavelength lasers operating in the wavelength range of 25–60 μm, which is not covered by currently available quantum cascade lasers. It is shown that the maximum temperature of stimulated emission is determined by the position of lateral maxima in the dispersion dependences in the first valence subband of the quantum well. Methods for suppressing nonradiative recombination in the structures with HgCdTe quantum wells are discussed.

Stimulated emission (SE) at wavelengths up to 20.3 μm (14.7 THz) is demonstrated from HgCdTe based quantum well heterostructures. The mitigation of Auger processes resulting from «graphene-like» energy spectrum in structures under study is exemplified. By studying the carrier lifetime via time resolved photoconductivity and transmission pump-probe measurements we show that further increase in SE wavelength is feasible and discuss the promising routes towards the 5 – 15 THz frequency domain, where quantum cascade lasers are scarce and HgCdTe lasers may be competitive to the prominent emitters.