The effect of hydrogenation in HgxCd1 − xTe thin films grown on p-CdTe (211) B substrates

Fourier transform infrared (FTIR) transmission, Hall effect, and nuclear resonance reaction measurements have been carried out to investigate the effect of hydrogenation on the deep levels and the hydrogen depth profiling in nominally undoped Hg_xCd_{1 − x}Te layers grown on undoped p-CdTe (211) B-orientation substrates by molecular beam epitaxy. After hydrogenation, the FTIR spectra showed that the transmittance intensity increased in comparison to that of the as-grown Hg_xCd_{1 − x}Te and that the absorption edge shifted to the short wavelength range. Hall effect measurements showed that the carrier concentration decreased and the mobility increased after hydrogenation. After hydrogenation, p-type Hg_xCd_{1 − x}Te is converted to n-type Hg_xCd_{1 − x}Te with high resistivity. Nuclear resonance raaction measurements show that the concentration and the penetration depth of the hydrogen atom in n-Hg_0.77Cd_0.23Te are 3.5% and 640 Å, respectively. The areal density of the hydrogen-containing layer at the surface of the hydrogenated n-Hg_0.77Cd_0.23Te film is 4.39 × 10¹⁵ atoms/cm². These results indicate that hydrogen atoms not only effectively passivate impurities or defects in the Hg_xCd_{1 − x}Te film but also change the carrier type of p-Hg_xCd_{1 − x}Te.