Nanostructured ZnSb films composited with Bi2Te3 topological insulators exhibit strongly unusual p-n conduction conversion upon crystallization

The crystallization of a local p-type ZnSb material can be deterministically tuned by doping with the n-type topological insulator Bi2Te3. Upon annealing, pure ZnSb shows a transition across three states, namely, high resistance, intermediate resistance, and low resistance. The metastable intermediate ZnSb phase has p-type conduction. Here, we find that the metastable ZnSb phase of the pure ZnSb film is significantly suppressed by Bi2Te3 doping, and the underlying conduction is changed into n-type conduction because Bi2Te3 doping induces a change in crystallization and simultaneously changes the type of crystalline phases. Nanoprecipitate formation and crystallization transition are the driving forces of the composition-dependent p-n conduction conversion. The X-ray diffraction, X-ray photoelectron and Raman spectroscopy results of the crystalline thin films suggest that the local bonding arrangement around Sb atoms changes. The Bi-Sb topological insulators are thus mainly responsible for the p-n transition and ultralow resistance shift shown by ZnSb-Bi2Te3 alloys.