Ab. Chen et al., COMPARISON OF IN1-XTIXSB AND HG1-XCDXTE AS LONG-WAVELENGTH INFRARED MATERIALS, Journal of electronic materials, 22(8), 1993, pp. 843-846
Cohesive energies, elastic constants, band structures, and phase diagr
am are calculated to evaluate the In1-xTlxSb alloy (ITA) as a long-wav
elength infrared (LWIR) material compared to Hg1-xCdxTe (MCT). To obta
in a 0.1 eV gap at zero temperature, the x value for ITA is estimated
to be x = 0.083 as compared to x = 0.222 for MCT. At this gap, ITA is
more robust than MCT because the cohesive energies order as InSb>TlSb>
CdTe>HgTe, and ITA has the stronger bonding InSb as the majority compo
nent. Although TlSb is found to favor the CsCl structure, ITA is a sta
ble alloy in the zincblende structure for low x values. However, our p
hase diagram indicates that it is difficult to grow the 0.1 eV gap ITA
from the melt, because above the eutectic the liquidus curve is flat,
and the solidus drops rapidly. Moreover, the width of the stable conc
entration range of the zincblende solid phase shrinks at low temperatu
res due to the presence of the CsCl structure.