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Chromium metal-induced nanocrystallization of amorphous silicon (a-Si) thin films is reported. The nanocrystalline nature of these films is confirmed from X-ray diffraction and Raman spectroscopy. Significantly, the deconvolution of Raman spectra reveals that the thin films were crystallized in a mixed phase of cubic diamond and wurzite structure as evidenced by the lines at 512 and 496 cm−1, respectively. The crystallite sizes were between 4 to 8 nm. Optical properties of the crystallized silicon, derived from spectral transmittance curves, revealed high transmission in the region above the band gap. Optical band gap varied between 1.3 to 2.0 eV depending on the nature of crystallinity of these films and remained unaltered with increase in Cr addition from 5 to 30%. This signifies that the electronic structure of the nanocrystalline Silicon films is not affected considerably inspite of the presence of metal silicides and the process of crystallization.

From first principles, the electronic and optical properties of zb-AlP are calculated. Based on calculated band structure, within the RPA approximation, the complex dielectric function and linear optical properties are calculated. With a band gap of 1.54 eV, zb-AlP shows typical wide band gap semiconductor like optical properties. The plasmon frequency ωp is found in the ultraviolet region.

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The Feynman Lectures on Physics, Vol. 1, are reviewed to illustrate some features common to many new physics courses.