Effect on lattice parameter and optical band gap of thallium incorporation in a GaInAs matrix

Using low temperature molecular beam epitaxy, we report the growth of thin layers of (Ga
_1-y
In
_y
)
_1-x
Tl
_x
As alloys on InP(001) substrates with thallium incorporation rates up to 12%. The lattice parameters and band gaps of these layers have been determined using Double Crystal X-ray diffraction and optical absorption techniques, respectively. The so-obtained experimental results are found to match the theoretical values predicted by Van Schilfgaarde et a1 for TlAs lattice parameter and band gap.