Growth of Cd1-xZnxTe Thin Films with High Zn Content by Close-Spaced Sublimation

The Cd1-xZnxTe films with a high x value of about 0.42 were achieved by close-spaced sublimation (CSS) method using a pre-alloyed CdZnTe source on the basis of two critical growth factors. A relatively high growth temperature is one of two key factors to achieve high Zn content in CdZnTe films. The x value of Cd1-xZnxTe varies from 0.10 to 0.42 as the substrate temperature changes from 100 to 500 degrees C under the pressure of 10 Pa. Moreover, it can be inferred that the sticking coefficient ratio of Zn to Cd is about 2.5-4 times at 500 degrees C than that at 400 degrees C. The other factor, more importantly, is the growth pressure, which should be below 10 Pa, while a high pressure of above 1000 Pa generally adopted in the Cd1-xZnxTe films using the CSS method always leads to Cd1-xZnxTe films with a low x value. The sudden increase of Zn vapor pressure under a growth pressure lower than 10 Pa is responsible for a high Zn content in the d(1-x)Zn(x)Te films. (C) 2016 Elsevier Ltd. All rights reserved.