Hydrogenation and double-layer passivation of mercury cadmium telluride (Hg1-xCdxTe or MCT) was studied and compared with passivation by a single CdTe layer. Two different passivated structures, namely CdTe/hydrogenated MCT and ZnS/CdTe/MCT, were investigated using Rutherford backscattering spectroscopy. No significant improvement in the compositional profile of CdTe/MCT was seen in a doubly passivated ZnS/CdTe/MCT structure, i.e. the presence of a ZnS passivating layer did not improve the compositional profile in CdTe/MCT structures. Similar to the CdTe/MCT sample, ZnS/CdTe/MCT was also found to have a 35nm-thick interlayer mixing region between CdTe and MCT. In CdTe/hydrogenated MCT the interface was found to be sharp and suggested complete blockage of Hg out diffusion by hydrogenation, and it was also observed that CdTe/hydrogenated MCT preserves its effectiveness in preventing the Hg out diffusion even after annealing at 80C in a vacuum. This improvement may be due to restriction of Hg vacancy diffusion by hydrogenation.

Improvement in the Ability to Block Hg Out-Diffusion from Hg1-xCdxTe by Hydrogenation. Anjali, P.Srivastava, S.Mohapatra, R.Pal, H.P.Vyas, B.R.Sekhar, H.K.Sehgal: Semiconductor Science and Technology, 2006, 21, 998-1001