Characterization of Low-Temperature Stress-Induced Crystallization of a-Si on Flexible Glass Substrates by Transmission Electron Microscopy and Raman Spectroscopy

The influence of external mechanical compressive and tensile stress on the crystallinity of amorphous silicon (a-Si) on thin, flexible glass substrates at low temperatures has been investigated by transmission electron microscopy, electron diffraction and Raman spectroscopy. Application of a compressive stress on an a-Si layer covered by a thin, 10Å thick nickel layer resulted in the formation of poly-crystalline silicon with an average grain size of about 0.2 μm at temperatures as low as 310°C. Conversely, application of an external tensile stress had only a small impact on the crystallinity and the layer remained predominately amorphous.