Raman, photoluminescence and optical absorption studies on nanocrystalline silicon

The Effect of Power Density on Diffusion Length and Energy Gap of a-Si:H and nc-Si:H Thin Films Prepared by PECVD Technique

“…A well--known Balberg plot of The values of X c for the samples are listed in Table. XRD spectra ( indicates that the exponential absorption tail, here, has a range wider than that of 250300 meV found by others [13]. In addition, this range is obviously wider than that 5060 meV found for a-Si:H samples [5,14,15].…”

Characterization of Si Nanocrystals

“…While amorphous Si has a broad transverse optical (TO) band around 480 cm À1 , bulk Si has a sharp TO band with a natural linewidth of approximately 3-4 cm À1 around 521 cm À1 at room temperature. On the other hand, this band for nanocrystalline Si shows a broadening and a shift to lower wavenumbers due to the phonon confinement effect [12][13][14][15][16][17]20]. A comparison of the Raman spectra shown in Figure 21.7 indicates the nanocrystal formation starts at temperatures between 700 and 800 C for the sample with an implantation dose of 2 Â 10 17 Si/cm 2 [12].…”

“…A model, WRL, developed by Richter, Wang and Ley; modified by others has widely been used in the literature [13][14][15][16][17]20]. This model stands on the multiplication of the wave function in an infinite crystal by a weighting function W D (r).…”

“…This model stands on the multiplication of the wave function in an infinite crystal by a weighting function W D (r). Gaussian and Sinc weighting functions have been successfully applied and widely reported in the literature to find the dimensions of Si nanocrystals [13][14][15][16][17]20]. However, the choice of the weighting function is arbitrary and results in quite different values at low dimensions of nanocrystals [15,16].…”

Room temperature photoluminescence mechanism of SiOx film after annealing at different temperatures

“…Such property of nc-Si has drawn much attention for its potential applications in the development of integrated opto-electronics based on the current Si technologies. Many researches have been done to explore the formation mechanism of nanometer scale Si by annealing SiO x film at different temperatures [3][4][5][6][7][8][9]. For SiO x film annealed at high temperatures such as 1100 1C, a phase separation process will take place as follows:…”