Emission Spectrum and Stability of Two Types of Electron–Hole Liquid in Shallow Si/Si1 – xGexSi Quantum Wells

Stability of electron–hole liquid in quantum wells

“…In recent studies [13][14][15], density functional theory was used to calculate the EHL energy and find the equilibrium density of electron-hole pairs in quantum wells. The calculation results for SiO 2 /Si and Si/SiGe quantum wells [13,14] are in good agreement with experimental data [4][5][6][7][8]. In this paper, we also use density functional theory to study EHL in quantum wells.…”

“…The calculated values of the equilibrium density for deep quantum wells are approximately in the same range (figure 3, curves 2 and 3). In [5][6][7], it was shown that a three-component EHL is formed in shallow SiGe/Si quantum wells. Its density depends on the depth of the quantum wells and the hole splitting and, for d = 1, varies between 0.4 and 0.3.…”

“…The properties of EHL in low-dimensional semiconductor structures are less studied. Recently, EHL was observed in Si/SiO 2 [3,4] and SiGe/Si [5][6][7][8][9] quantum wells and in transitionmetal dichalcogenides (monolayer MoS 2 [10,11] and multilayer MoTe 2 [12]). The condensation of excitons in monolayer MoS 2 into EHL with very high electron-hole pair densities on the order of 4 × 10 13 cm −2 and a high critical temperature of T c ≈ 500 K was reported in [10].…”