[13p-A201-1~9] Current topics and future prospects of amorphous materials and their device applications

[13p-A201-4] Gap states and carrier properties in Ge₂Sb₂Te₅ films

〇Tamihiro Gotoh¹ (1.Gunma Univ.)

Keywords:phase change memory, density of states, photothermal deflection spectroscopy

Ge₂Sb₂Te₅ thin films have been used in phase change memories. In order to improve the reliability of the memory operation, it is essential to understand the levels in the gap and the carrier characteristics affected by the high electric field. We observed weak optical absorption related to the gap states of Ge₂Sb₂Te₅ thin films using photothermal deflection spectroscopy (PDS). We clarify the density of states of amorphous and crystalline, and consider the carrier generation mechanism.