High-Pressure Preparation of High-Density Cu2ZnSnS4 Materials**Supported by the National Natural Science Foundation of China under Grant Nos 10874178, 11074093, 61205038 and 11274135, the National Found for Fostering Talents of Basic Science under Grant No J1103202, the Ph.D. Programs Foundation of Ministry of Education of China under Grant No 20120061120011, the Open Project of State Key Laboratory of Superhard Materials of

Abstract

High-density Cu2ZnSnS4 (CZTS) materials are prepared via the mechanical alloying and high pressure sintering method using Cu2S, ZnS and SnS2 as the raw materials. The morphological, structural, compositional and electrical properties of the materials are investigated by using x-ray diffraction, scanning electron microscopy, and energy dispersive x-ray spectroscopy, as well as by the Raman scattering and the Hall Effect measurements. The CZTS synthesized under 5 GPa and 800°C shows a p-type conductivity, with a resistivity of 9.69 × 10−2 Ω·cm and a carrier concentration of 1.45 × 1020 cm−3. It is contributed to by the large grains in the materials reducing the grain boundaries, thus effectively reducing the recombination of the charge carriers.