Phase modification by instantaneous heat treatment of Sb2S3 films and their potential for photothermal optical recording

Abstract

The Sb2S3 films subjected to instantaneous heat treatment at various temperatures in air for a short duration of a few seconds show a systematic phase modification from an amorphous to a crystalline state. Structural and morphological analyses show an amorphous to crystalline transformation around 162 °C consistent with the DTA result. The compositional analysis (ESCA) shows an increasing loss of sulphur content in the film as the function of treatment temperatures. The optical properties reveal the changing optical constants and energy gap of the film with the treatment temperatures. The observed degree of optical contrast with heat-treatment temperatures indicates the possibility of photo-thermal optical storage in these films. The results of the real-time photo-thermal optical recording in these films compare well with those of the heat-treatment experiment. The homogeneity of the film over a large area, the stability of the modified phase, use of low laser power for recording, and the formation of a clean boundary of the recorded area, etc., indicate a possible use of Sb2S3 films for write-once-read-many times kind of optical storage applications.