Experimental Activation Energy for Solid Phase Crystallization of Amorphous Silicon Thin Films at Elevated Temperatures Using Vertical-Cavity Surface-Emitting Laser-Based Infrared Heating

Abstract

Vertical cavity surface-emitting lasers were applied to rapid heating of amorphous Si (a-Si) thin films using high-power infrared illumination at a wavelength of 980 nm, allowing for a high heating rate of up to 200°C/sec, temperature control of less than 0.1°C, and temporal resolution of 0.1 sec. The refined temperature control enabled us to accurately investigate the rapidly evolving period of crystallization in a-Si at high speed. The crystallinity and surface morphology were probed using Raman spectroscopy, UV-visible spectroscopy, and atomic force microscopy. The temperature-dependent crystallinity was quantified by fitting the annealing duration time with a sigmoidal curve. Based on the crystallization times in association with the Arrhenius relation, the activation energy for crystallization was calculated to be 2.6 eV, which is in excellent agreement with those obtained for low-temperature solid phase crystallization.

Vertical-cavity surface-emitting laser (VCSEL)-based ultrafast photonic sintering of solid oxide fuel cells (SOFCs): prospects for time-efficient/two-dimensional scalability to large-sized SOFCs

“…Despite the distinctive features of large-area IR lasers, no literature has employed VCSEL-based photonic processing for sintering functional ceramic materials. Only our group reported the application of VCSEL-assisted crystallization of amorphous Si thin films, 20 which can be applied to low-temperature polycrystalline Si thin film transistor technology in association with high-performance active-matrix flat panel displays and incorporated the Si wafer as a susceptor in heating the thin film-containing glass plates. In this work, we demonstrate a visually traceable and accurately controlled photonic sintering approach for SOFCs, for the first time in the application of VCSEL-based irradiation to sintering to the best of the authors' knowledge.…”