Abstract:
The absorption and extinction spectra of Ge nanocrystals in silica formed by ion implantation are studied using photothermal deflection and transmission spectroscopies. It is found that scattering makes a significant contribution to the extinction spectrum, damping the spectral features and resulting in a Rayleigh scattering-like omega4 dependence. In contrast, the spectra measured by photothermal deflection clearly show features such as the E1/E1 + Delta1 transitions. The Tauc gap is extracted to be ~0.7±0.1 eV.
