Temperature stability of the refractive index and the direct bandedge in TlInGaAs quaternary alloys

摘要

TlInGaAs quaternary alloy layers were grown on InP substrates by gas-source molecular-beam epitaxy. Refractive index dispersions were determined at the temperature range of 300-340 K in the photon-energy region below and a little above the direct bandedge E_(0) by the optical reflectance measurements. The temperature dependence of the refractive index was analyzed with the first-order Sellmeier equation. The temperature dependence of the E_(0) edge was also determined by the absorption measurements. It was found that the temperature coefficients of both refractive index and E_(0) edge of TlInGaAs are much smaller than those for InGaAs. These results facilitate the fabrication of the temperature-stable-wavelength optoelectronic devices using this alloy system.