Gas source MBE growth and characterization of TlInGaP and TlInGaAs layers for long wavelength applications

New III-V semiconductors TIInGaP and TIInGaAs (Tl composition of less than 0.1) are grown on InP substrates by gas source molecular beam epitaxy. They are proposed for long wavelength optical devices as well as temperature-in sensitive wavelength laser diodes. Grown layers are characterized by the me asurements on the temperature variation of photoconductance and photolumine scence. It is observed that the bandgap energy shows small-temperature vari ation suggesting the existence of temperature-independent bandgap energy in these material systems for the layers with increased Tl composition. (C) 1 999 Elsevier Science B.V. All rights reserved.