The interdiffusion of iso-electronic constituents across hetero-interfaces during the liquid-phase epitaxial growth of Hg1-xCdxTe on Cd1-yZnyTe and CdTe1-ySey substrates was measured, where x was equal to 0.2 or 0.5, and y was equal to 0, 0.04 or 0.07. This was done by means of energy-dispersive X-ray spectroscopy and secondary ion mass spectrometry. It was found that the interdiffusion coefficients of the constituent cation components (Cd, Hg) depended upon the x and y values, for growth temperatures ranging from 450 to 460C. Their asymmetrical concentration profiles exhibited steep slopes in the Cd-rich substrate and long tails in the Hg-rich layer. The concentration profiles of Zn and Se could be described by constant diffusion coefficients. The diffusivity of Cd could be described by the expressions:
yZn = ySe = 0: D (cm2/s) = 2.1 x 10-11exp[-8.2x]
yZn = 0.046: D (cm2/s) = 8.0 x 10-12exp[-4.7x]
yZn = 0.067: D (cm2/s) = 2.0 x 10-12exp[-0.5x]
ySe = 0.041: D (cm2/s) = 3.0 x 10-11exp[-8.0x]
Non-Abruptness of Hetero-Interfaces during LPE Growth of (Hg,Cd)Te on (Cd,Zn)Te and Cd(Te,Se) Substrates. I.Utke, W.Frentrup, I.Hähnert, H.Kirmse, O.Müller, M.Schenk, M.Winkler: Journal of Crystal Growth, 1996, 162, 126-34
Table 2
Diffusivity of I in CdTe
Temperature(C) | Source | Sample | Section | D(cm2/s) |
20 | I | bulk | 1 | 3 x 10-17 |
20 | I | bulk | 2 | 1 x 10-16 |
20 | I | bulk | 3 | 2.5 x 10-15 |
20 | I | bulk | 4 | 3 x 10-14 |
270 | CdI2 | bulk | 1 | 2 x 10-18 |
270 | CdI2 | bulk | 2 | 3 x 10-17 |
270 | CdI2 | bulk | 3 | 4 x 10-15 |
270 | CdI2 | bulk | 4 | 3 x 10-12 |
20 | CdI2 | bulk | 1 | 2 x 10-20 |
20 | CdI2 | bulk | 2 | 6 x 10-19 |
20 | CdI2 | bulk | 3 | 3 x 10-17 |
20 | CdI2 | bulk | 4 | 2 x 10-14 |
85 | CdI2 | epitaxial | 1 | 5 x 10-20 |
85 | CdI2 | epitaxial | 2 | 4 x 10-18 |
85 | CdI2 | epitaxial | 3 | 3 x 10-16 |
85 | CdI2 | epitaxial | 4 | 9 x 10-14 |