Электрофизические и фотолюминесцентные исследования сверхрешeток \LT-GaAs/GaAs : Si\, выращенных методом молекулярно-лучевой эпитаксии на подложках GaAs с ориентацией (100) и (111)А

Abstract

The results of studying semiconductor structures proposed for the first time and grown, which combine the properties of LT-GaAs with p -type conductivity upon doping with Si, are presented. The structures are {LT-GaAs/GaAs:Si} superlattices, in which the LT-GaAs layers are grown at a low temperature (in the range 280–350°C) and the GaAs:Si layers at a higher temperature (470°C). The p -type conductivity upon doping with Si is provided by the use of GaAs(111)A substrates and the choice of the growth temperature and the ratio between As_4 and Ga fluxes. The hole concentration steadily decreases, as the growth temperature of LT-GaAs layers is lowered from 350 to 280°C, which is attributed to an increase in the roughness of interfaces between layers and to the formation of regions depleted of charge carriers at the interfaces between the GaAs:Si and LT-GaAS layers. The evolution of the photoluminescence spectra at 77 K under variations in the growth temperature of LT-GaAs is interpreted as a result of changes in the concentration of Ga_As and V _Ga point defects and Si_Ga– V _Ga, V _As–Si_As, and Si_As–Si_Ga complexes.

Energy States of Particles in a Quantum Sized Structure With a Complex Shaped Band Diagram

“…At the same time, the maximum SHG coefficient does not mean at all that the observed intensity of the generated radiation at the doubled frequency will necessarily be maximum. Indeed, in the double resonance regime, both lasing and generated radiation can be strongly absorbed, i.e., resonant optical transitions can lead to strong lasing at the frequency 2ω, but at the same time to strong absorption at frequencies ω and 2ω [1][2][3][4][5][6].…”