Pressure-induced electrical transport properties, texture, and microstructure of the (Bi,Sb)2Te3 alloys

Abstract

High pressure as an effective strategy was employed to synthesize and modulate the electrical transport properties of (Bi,Sb)₂Te₃ alloys. Intrinsic point defects could be significantly regulated via high pressure, inducing a suitable donor-like effect to optimize the carrier concentration. The texture and microstructure were improved with high pressure, and a nanograin with (00l) orientation was observed in the (Bi,Sb)₂Te₃ matrix, suggesting that high pressure could facilitate the recrystallization of lattice defects along the (00l) orientation. Based on the synergistic effect of high pressure on intrinsic point defects, texture, and microstructure, the carrier concentration and mobility are regularly modulated, resulting in the room-temperature power factor of the (Bi,Sb)₂Te₃ alloys exhibiting a strong correlation with pressure. Hence, these important results here provide a prospective strategy in the improvement in the electrical transport properties of the Bi₂Te₃-based alloys according to the rational design of intrinsic point defects, texture, and microstructure with high pressure.