Electrical and optical properties of indium-modified Se₂Sb ₂Te₆ films

The electrical and optical characteristics of indium-doped Se ₂Sb₂Te₆ phase-change alloy are studied in this paper. It is found that adding indium to Se₂Sb₂Te ₆ alloy increases its amorphous-crystalline transition temperature, T_C, and reduces the electrical conduction activation energy. The capacitance-temperature measurements showed a drastic change in the capacitance of the modified film as the temperature approaches T_C and eventually the capacitance becomes negative and nonlinear. The negativity and nonlinearity in the capacitance-voltage dependence can be attributed to the growth of conductive crystalline islands with increasing temperature.