Structural Phase Transition and Electrical Transport Properties of CuInS2 Nanocrystals under High Pressure

The structural and electrical transport behaviors of CuInS2 nanocrystals under high pressure have been investigated using angle dispersive X-ray diffraction (ADXRD), in situ Hall effect, and temperature-dependent electrical resistivity measurements. A pressure-induced irreversible structure transformation from tetragonal phase to cubic phase has been confirmed at 10.9 GPa, which has noticeably elevated the transition pressure (1.4 GPa) in nanocrystals compared to the bulk CuInS2. In addition, the pressure-dependent electrical transport parameters, such as Hall coefficient, Hall mobility, carrier concentration, and electrical resistivity, all show dramatic changes around 11 GPa, implying that the pressure-induced structure transformation of CuInS2 can bring about a series of changes in the carrier transport properties. Specifically, the sign of the Hall coefficient is changed from negative to positive around 12 GPa, implying that CuInS2 undergoes a carrier-type inversion from n- to p-type. In addition, the...