Study on the phase change behavior of nitrogen doped Bi2Te3 films

Bi2Te3 has been widely used as thermoelectric material due to its overall good properties, such as low thermal conductivity, high electrical conductivity, and flexible atoms arrangement for structural optimization et al. However, its potential in phase change memory (PCM) application is not well evaluated due to its unstable amorphous state. In this work, stability of amorphous Bi2Te3 has been improved by N doping. Crystallization temperature of 175 °C and data retention of 43.6 °C have been achieved. Smaller and defective grains have been directly observed. Abnormal volume expansion of 7.2% has been observed after crystallization. Low-power consumption and good reversible phase change ability of N doped Bi2Te3 has been verified in PCM cell.