Calculation of Diffusion‐limited Growth of Hg 1− x Cd x Te Epilayers on CdTe from Te‐rich Melts by Step‐Cooling LPE

Calculations of layer thicknesses and composition profiles in Hg 1− x Cd x Te layers on CdTe substrates for the growth from Te‐rich melts have been carried out for liquidus temperatures of 460 °C, 480 °C, and 500 °C. This has been made on the basis of the multicomponent diffusion model of S MALL and G HEZ and the solid‐liquid phase relation of B RICE . It could be shown that growth velocity increases only slightly with rising liquidus temperature. On the other hand, the interdiffusion velocity of Hg and Cd in the solid increases remarkably at a higher temperature. Therefore, to get layers with a constant x ‐value a higher supersaturation of the melt is necessary. The x ‐value decreases with rising supercooling by about 0.003 K −1 . To demonstrate the thermodynamically and kinetically advantageous properties of CdTe as substrate material, comparative calculations for a “hypothetical” HgTe substrate have been involved.