Dipolar electron-hole liquid in a double-well SiGe/Si heterosystem

18th Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics

Akmaev, M.A.^1,2 ; Burbaev, T.M.^1

Lebedev Physical Institute, Russian Academy of Sciences, Leninskiy prospect 53, Moscow

119991, Russia^1

Moscow State University, Faculty of Physics, Leninskie Gory 1-2, Moscow

119991, Russia^2

关键词: Dipolar excitons;    Double well;    Electron hole liquids;    Heterosystems;    High excitation levels;    Kinetics measurements;    Liquid helium temperature;    SiGe/Si;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/816/1/012016/pdf
DOI  :  10.1088/1742-6596/816/1/012016

来源: IOP

【 摘 要 】

The transition from a dipolar to a spatially direct electron-hole liquid in two-dimensional layers of a type-II (buffer Si1-yGey)/tSi/sSi1-xGex/tSi/(cap Si1-yGey) heterostructure is investigated by photoluminescence spectroscopy at liquid-helium temperatures at high excitation levels. The transition takes place upon a reduction of the thickness of the sSi1-xGexlayer, which forms a quantum well for holes in the valence band and a barrier in the conduction band separating the electron quantum wells (tSi layers). The main characteristics of both types of electron-hole liquid are determined. The lifetime of dipolar excitons is determined from photoluminescence kinetics measurements.