Open AccessОсобенности ионизации доноров кремния и рассеяние электронов в псевдоморфных квантовых ямах AlGaAs/InGaAs/GaAs при сильном одностороннем delta-легировании
Author(s) -
D. A. Safonov,
А. Н. Виниченко,
Н. Каргин,
И. С. Васильевский
Publication year - 2018
Publication title -
pisʹma v žurnal tehničeskoj fiziki
Language(s) - English
Resource type - Journals
eISSN - 1726-7471
pISSN - 0320-0116
DOI - 10.21883/pjtf.2018.04.45636.16915
Subject(s) - heterojunction , doping , condensed matter physics , quantum tunnelling , electron , quantum well , silicon , materials science , fermi level , limiting , electron mobility , effective mass (spring–mass system) , quantization (signal processing) , fermi gas , conduction band , optoelectronics , physics , optics , mechanical engineering , laser , engineering , quantum mechanics , computer science , computer vision
The influence of the concentration of silicon donors on the electron-transport properties of pseudomorphous Al_0.25Ga_0.75As/In_0.2Ga_0.8As/GaAs quantum wells (QWs) in heterostructures with heavy unilateral δ-doping by Si atoms was studied in a broad temperature interval (2.1–300 K). High electron mobility (up to 35700 cm^2/(V s)) at T = 4.2 K was observed at a 2D (sheet) electron density of 2 × 10^12 cm^–2 in the QW. A band mechanism limiting the ionization of donors at an increased level of doping is described. The nonmonotonic variation of electron mobility with increasing silicon concentration is explained. A growth in the mobility is related to increase in the Fermi momentum and screening, while the subsequent decay is caused by tunneling-induced degradation of the spacer layer with decreasing potential of the conduction band in the region of δ-Si layer. It is shown that the effect is not related to filling of the upper subband of dimensional quantization.