Different crystallization processes of as-deposited amorphous Ge2Sb2Te5 films on nano- and picosecond single laser pulse irradiation

• Published in: Physica. B, Condensed matter Condensed matter, 2012-07, Vol.407 (13), p.2447-2450
• Main Authors: Zhang, Ke, Li, Simian, Liang, Guangfei, Huang, Huan, Wang, Yang, Lai, Tianshu, Wu, Yiqun
• Format: Article
• Language: English
• Subjects: Condensed matter; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystallization; Exact sciences and technology; Extra-non-equilibrium process; Growth from solid phases (including multiphase diffusion and recrystallization); Irradiation; Lasers; Materials science; Methods of crystal growth; physics of crystal growth; Nanocomposites; Nanomaterials; Nanosecond laser pulse; Nanostructure; Phase-change material; Physical radiation effects, radiation damage; Physics; Picosecond laser pulse; Recalescence; Structure and morphology; thickness; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Ultraviolet, visible, and infrared radiation effects (including laser radiation)
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2012.03.044

The crystallization dynamics of as-deposited amorphous Ge2Sb2Te5 films induced by nano- and picosecond single laser pulse irradiation is studied using in situ reflectivity measurements. Compared with nanosecond laser pulse, the typical recalescence phenomenon did not appear during the picosecond laser pulse-induced crystallization processes when the pulse fluence gradually increased from crystallization to ablation threshold. The absence of melting and recalescence phenomenon significantly decreased the crystallization time from hundreds to a few tens of nanoseconds. The role of pulse duration time scale on the crystallization process is qualitatively analyzed.