TlGaP layers grown on GaAs substrates by gas source molecular beam epitaxy

TlGaP layers are grown on GaAs substrates by gas source molecular beam epitaxy. TlGaP is a constituent ternary alloy of the new III–V compound semiconductor TlInGaP, a material which can be used for 0.9 µ m to over 10 µ m laser diodes and for temperature-insensitive-wavelength laser diodes. TlGaP on GaAs shows phase separation into three stable compositions: TlGaP nearly lattice-matched to GaAs, GaP-like TlGaP and TlP-like TlGaP. By adjusting Tl and Ga fluxes, TlGaP layers without phase separation are grown. Photoconductance measurement on TlGaP shows absorption in the 1.3 µ m wavelength region as well as the small temperature variation of band-gap energy, as expected.