Doping of dilute nitride compounds grown by liquid phase epitaxy

Abstract

The doping of dilute nitrides is an important point of the growth and processing technology for different optoelectronic devices based on these compounds. In this paper, both intentional and nonintentional doping of InGaAsN and GaAsSbN have been investigated by temperature-dependent Hall effect measurements. Dilute nitrides layers have been grown by low-temperature (Tcryst < 600 °C) liquid-phase epitaxy (LPE). The chemical elements Sn and Mg have been chosen as n-type and p-type dopants, respectively. All nominally undoped InGaAsN layers are n-type with free carrier concentration about one order of magnitude higher than layers not containing nitrogen and grown by LPE. This makes it difficult to obtain epitaxial layers with p-type conductivity with these compounds. However, high-quality n-type, p-type and nearly compensated GaAsSbN layers have been successfully grown covering a large range of carrier concentrations from 1015 to 6×1018 cm−3. The quality of the GaAsSbN layers has been evidenced by a good photoresponse with a low energy threshold extended down to 1.2 eV as obtained by surface photovoltage spectroscopy.