Characteristics at high electric fields in amorphous Ge2Sb2Te5 films

Current–voltage (I–V) characteristics have been studied in as-deposited amorphous Ge2Sb2Te5 films. At low electric fields, ohmic behavior is observed. On the other hand, at high electric fields (E > 106 V/m) the current becomes non-ohmic. Analysis of the data shows the existence of Poole–Frenkel conduction in which ln I vs V1/2 curves are found to be straight lines. Pre-switching behaviors are also discussed from electrode configuration.