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Abstract Abstract Abstract Abstract. . . .Cd vacancies in cadmium zinc telluride(CdZnTe) crystals have an important effect on the crystal properties.In this paper, position distribution and concentration change of Cd vacancy in CdZnTe crystal grown by the temperature gradient solution growth (TGSG) were investigated by positron annihilation technology(PAT) , which was based on the potential energy distribution and probability density of the positron in the crystal. The results showed that, the density of Cd vacancy increased obviously from the first-to-freeze to stable growth of the ingots, while decreased along the radial direction of the ingots

High Thermoelectric and Reversible <i>p‑n‑p</i> Conduction Type Switching Integrated in Dimetal Chalcogenide

The subject of the involved phase transition in solid materials has formed not only the basis of materials technology but also the central issue of solid-state chemistry for centuries. The ability to design and control the required changes in physical properties within phase transition becomes key prerequisite for the modern functionalized materials. Herein, we have experimentally achieved the high thermoelectric performance (ZT value reaches 1.5 at 700 K) and reversible <i>p-n-p</i> semiconducting switching integrated in a dimetal chalcogenide, AgBiSe₂ during the continuous hexagonal–rhombohedral–cubic phase transition. The clear-cut evidences in temperature-dependent positron annihilation and Raman spectra confirmed that the <i>p-n-p</i> switching is derived from the bimetal atoms exchange within phase transition, whereas the full disordering of bimetal atoms after the bimetal exchange results in the high thermoelectric performance. The combination of <i>p-n-p</i> switching and high thermoelectric performance enables the dimetal chalcogenides perfect candidates for novel multifunctional electronic devices. The discovery of bimetal atoms exchange during the phase transition brings novel phenomena with unusual properties which definitely enrich solid-state chemistry and materials science