This may be due to the disorder (amorphous nature) present in the films. This peak also shows a slight blueshift with the increase in Cd content. Therefore, the peak observed at 425 nm agrees well with that of the reported results . Figure 4 Photoluminescence spectra at various concentrations of Cd in thin films of a-(PbSe) 100−x Cd
x nanoparticles. The understanding of optical and electrical processes in lead chalcogenide materials in nanoscale is of great interest for both fundamental and technological points of view. In recent years, owing to their very interesting physical properties, this particular material has raised a considerable deal of research interest followed by technological applications in the field BIIB057 supplier of micro/optoelectronics. Significant research efforts have
been focused to the study of the optical and electrical properties of this KU-57788 cost compound in thin film formation because the optimization of device performance requires a well-established knowledge of these properties of PbSe and metal-doped PbSe thin films. Here, we have studied the optical absorption, reflection, and transmission of amorphous thin films of (PbSe)100−x Cd x nanoparticles as a function of the incident wavelength in the range of 400 to 1–200 nm. The optical absorption studies of materials provide a simple approach to understand the band structure and energy gap of nonmetallic materials. Normally, the absorption coefficient is measured in the high and intermediate absorption regions to study the optical properties of materials.
It is one of the most important means of determining the band structures of semiconductors. On the basis of measured optical density, Vorinostat cell line we use the following relation to estimate the values of the absorption coefficient : (1) where OD is the optical density measured at a given layer thickness (t). On the basis of the calculated values of absorption coefficient, we have observed that the value of absorption coefficient increases with the increase in photon energy for all the studied thin films of a-(PbSe)100−x Cd x nanoparticles. During the absorption MLN2238 price process, a photon of known energy excites an electron from a lower to a higher energy state, corresponding to an absorption edge. In the case of chalcogenides, we observe a typical absorption edge, which can be broadly attributed to one of the three processes: (1) residual below-gap absorption (2) Urbach tails, and (3) interband absorption. Highly reproducible optical edges are being observed in chalcogenide glasses. These edges in chalcogenides are relatively insensitive to the preparation conditions, and only the observable absorption  with a gap under equilibrium conditions accounts for the first process.