Orientation Control of Large-Grained Si Films on Insulators by Thickness-Modulated Al-Induced Crystallization
2013; American Chemical Society; Volume: 13; Issue: 4 Linguagem: Inglês
10.1021/cg4000878
ISSN1528-7505
AutoresRyohei Numata, Kaoru Toko, Noriyuki Saitoh, Noriko Yoshizawa, Noritaka Usami, Takashi Suemasu,
Tópico(s)Silicon and Solar Cell Technologies
ResumoThe thickness-modulated Al-induced crystallization technique enables us to control the orientation of polycrystalline Si films on insulators. The amorphous Si film on a SiO2 substrate was crystallized at a low temperature (425 °C) through the layer exchange between Si and catalytic Al layers. Electron backscattering diffraction (EBSD) measurements revealed that the crystal orientation of the grown Si layer varied significantly depending on the Al/Si thickness: The [111]-orientation fraction reached 97% for the 50-nm-thick sample and the [100]-orientation fraction 88% for the 200-nm-thick sample. This mechanism was discussed in terms of the heterogeneous nucleation energy. The 50-nm-thick sample provided the maximum Si grain-size as large as 68-μm diameters. These large-grained Si films with controlled-orientations are promising epitaxial templates for advanced Si-based thin-film solar cells.
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