Electrical and Optical Properties of (mercury, Cadmium)tellurium Accumulation Layers.

Available from UMI in association with The British Library. Requires signed TDF. Schubnikow-de Haas and parallel field magnetoresistance measurements were performed on accumulation layer electrons at anodic oxide films on n-Hg_{0.8 }Cd_{0.2}Te and n-Hg_{0.7}Cd _{0.3}Te, and used to deduce the number and occupancies of the populated subbands. Existing erroneous data by other authors was corrected. Parallel field magnetoresistance measurements on the above systems yield structures due to the depopulation of the subbands. This data was compared with results from other systems and a universal relationship between depopulation field and surface carrier density suggested. A persistent negative photoconductivity was observed in the above systems, due to excitation of electrons across the anodic oxide band gap and their recombination with charged impurities, thus reducing the charge in the accumulation layer. Cyclotron resonance of accumulation layer electrons on n-Hg_{0.8}Cd _{0.2}Te revealed subband effective masses lower than theoretically predicted: comparisons with results from other systems gave evidence that the semiconductor close to the anodic oxide can be Hg-rich or rare. Resonant 2D magnetopolarons were observed, the subband electrons showing apparent coupling to the TO or LO phonon depending on subband index. Tilted field cyclotron resonance revealed pseudo three dimensional behaviour by the subbands and effects thought to be due to skipping orbits, not previously seen in semiconductor systems. The coupling of these orbits to radiation was shown to differ from theoretical predictions. Cyclotron resonance of accumulation layer electrons on n-Hg_{0.7}Cd _{0.3}Te was observed, and the i = 0 subband effective mass deduced. Cyclotron resonance measurements on bulk n-Hg _{0.8}Cd_ {0.2}Te revealed a minimum in the linewidth as a function of magnetic field, previously only observed in n-InSb. The effective mass varied faster with temperature than theoretically predicted, possibly a consequence of alloy disorder. Measurements of the i = 0 subband g-factor in both n-Hg_{0.8}Cd _{0.2}Te and n-Hg_ {0.7}Cd_{0.3} Te accumulation layers indicated that the g-factor was not strongly enhanced, in contrast to results in other systems.