Hg <sub> 1-x </ Sub> Mn <sub> X </ Sub> Te Crystal Growth Modified And Performance Characterization

Hg_1-xMn_xTe has very similar structure and optical-electronic properties as that of Hg_1-xCd_xTe, but possesses some superiorities over Hg_1-xCd_xTe in some aspects, therefore, Hg_1-xMn_xTe becomes a perspective substitute for Hg_1-xCd_xTe as IR detector material. Preparation of high quality Hg_1-xMn_xTe crystal is of vital importance to the development of the material and relative device. Several ingots of Hg_1-xMn_xTe were produced by Bridgman method, and their optical and electronical properties were tested. The measurements on composition distribution, carrier concentration and mobility revealed that most of its properties could not satisfy the requirements of IR detector at the as-grown state. Further treatments are necessary.The electronic properties of Hg_1-xMn_xTe are dominated by defects, including native point defects (vacancies, interstitials, antisites, and complexes ), extended defects (all types of dislocations, grain boundaries, precipitates, melt spots, etc.), and undesired impurities. A new etchant suitable for Hg_1-xMn_xTe has been found. This etchant can show different defects, such as dislocations, grain boundaries, twins, Te-rich inclusions and precipitates etc., on different planes.Observation on the variation of surface morphology during the etching process indicates that the grain boundary and Te precipitates will be shown earlier than the dislocations.Slices of Hg_1-xMn_xTe crystals were annealed under low temperature in Hg atmosphere to improve their electronic properties. The electronic properties of annealed slices and coterminous non-annealed slices were evaluated by Hall measurement. The as-grown Hg_1-xMn_xTe crystals are usually P-type semiconductors, which can be successfully converted into N-type by annealing under given conditions.