Papers by Author: A.M. Funde

Abstract: In this work we report synthesis and characterization of hydrogenated nanocrystalline silicon (nc-Si:H) thin films by plasma chemical vapor deposition (P-CVD) method at 200 0C on glass substrates. Film properties are carefully and systematically investigated as a function of argon (Ar) flow rate. Characterization of these films with Raman spectroscopy revealed that the addition of Ar into SiH4-H2 plasma endorses the growth of crystallinity in the films. The Fourier transform infrared (FTIR) spectroscopic analysis showed that with increasing Ar flow rate the hydrogen bonding in the films shifts from mono-hydride (Si-H) to di-hydride (Si-H2) and (Si-H2)n complexes. The hydrogen content in the films was found < 7 at. % over the entire range of studied Ar flow rate. The band gap of nc-Si:H films was found to be higher than hydrogenated amorphous silicon (a-Si:H) films (> 2 eV). The nc-Si:H films with dark conductivity 1.3x10-7 S/cm having deposition rate as high as 2.5 Å/s and of crystalline fraction 98 % have been obtained.

Abstract: Herein, we report the fabrication of anthracene nanostructures and, in turn, their thin films at the air-water interface by recrystallization at the liquid-liquid interface. This method is simple, inexpensive and allows the deposition of anthracene nanoparticulate thin films on large and a variety of substrates. The virgin films were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Hot Stage Polarizing Microscopy and UV-Visible spectroscopy. Interestingly, it was found that these thin films are comprised of nanosized bushy clusters of anthracene molecules as revealed by TEM. Also, with increase in the thickness of the films, the formation of irregular microtapes was evinced by SEM. The absorption spectra reveals the presence of 2 excitonic peaks for the lowest dip sample (10 dips) whereas the spectra recorded for higher dip samples (20 dips, 30dips, 40dips) closely match with that of pure anthracene in chloroform solution. The dramatic reduction in the melting point as revealed by hot stage polarizing microscopy is the salient feature of the work.