TlInGaAs quaternary layers are grown on InP substrates bg gas-source molecu
lar beam epitaxy (MBE) for the first time. The application of TlInGaAs was
proposed for long-wavelength optical devices as well as temperature-insensi
tive wavelength laser diodes. During the growth, RHEED (reflection high-ene
rgy electron diffraction) patterns show(2 x 2) reconstructions. Successful
growth of TlInGaAs is confirmed with X-ray diffraction measurements. PL emi
ssion is observed and the temperature variation of PL peak energy is as sma
ll as 0.1 meV/K.