Absorption Coefficient Of Semiconductor Research Articles

Doping Effects and Relationship between Energy Band Gaps, Impact of Ionization Coefficient and Light Absorption Coefficient in Semiconductors

The doping process is very important in semiconductor technology that is widely used in the production of electronic devices. The effects of doping on the resistivity, mobility and energy band gap of semiconductors are significant and can greatly impact the performance of electronic devices. This thesis aims to investigate the impact of doping on the resistivity, mobility, energy band gap, impact of ionization coefficient, and light absorption coefficient of semiconductors. The study involves an in-depth analysis of the electronic properties of doped semiconductors and their behavior in various conditions. This thesis will provide a comprehensive understanding of the impact of doping on the electronic properties of semiconductors. The energy band gap, impact of ionization coefficient, and Light absorption coefficient were observed in this thesis. In the experimental result, the relation between energy band gap and atomic density, light absorption coefficient and atomic density, impact ionization and atomic density, impact ionization coefficient and Light absorption coefficient, resistivity and mobility has been found.

Mathematical modeling determination coefficient of magneto-optical absorption in semiconductors in presence of external pressure and temperature

The calculation of the coefficients of magneto-optical absorption in semiconductors at different temperatures and pressures is carried out. A formula for the temperature dependence of the oscillations of the combined density of states by the Kane dispersion law is obtained. Mathematical modeling has been carried out that determines the magneto-optical absorption coefficient in semiconductors in the presence of external influences. A new method for determining the magneto-optical absorption coefficient in semiconductors in the presence of pressure and temperature is proposed. The correspondence of simulation results with experimental data is shown.

Calculation of the ultimate efficiency of p-n-junction solar cells taking into account the semiconductor absorption coefficient

Calculation of the ultimate efficiency of p-n-junction solar cells taking into account the semiconductor absorption coefficient

A linear relationship between the Hall carrier concentration and the effective absorption coefficient measured by means of photothermal radiometry in IR semi-transparent n-type CdMgSe mixed crystals

In this work we demonstrate the ability to measure the effective infrared absorption coefficient in semiconductors by a photothermal infrared radiometry (PTR) experiment, and its correlation with the Hall carrier concentration. The amplitude and phase of the PTR signal were measured for Cd1−xMgxSe mixed crystals, with the magnesium content varying from x = 0 to x = 0.15. The PTR experiments were performed at room temperature in thermal reflection and transmission configurations using a mercury cadmium telluride infrared detector. The PTR data were analyzed in the frame of the one-dimensional heat transport model for infrared semi-transparent crystals. Based on the variation of the normalized PTR phase and amplitude on the modulation frequency, the thermal diffusivity and the effective infrared absorption coefficient were obtained by fitting the theoretical expression to experimental data and compared with the Hall carrier concentration determined by supplementary Hall experiments. A linear relationship between the effective infrared absorption coefficient and the Hall carrier concentration was found which is explained in the frame of the Drude theory. The uncertainty of the measured slope was 6%. The value of the slope depends on (1) the sample IR absorption spectrum and (2) the spectral range of the infrared detector. It has to be pointed out that this method is suitable for use in an industrial environment for a fast and contactless carrier concentration measurement. This method can be used for the characterization of other semiconductors after a calibration procedure is carried out. In addition, the PTR technique yields information on the thermal properties in the same experiment.

Theoretical analysis of interband optical absorption in an external electric field

We study theoretically the interband optical absorption coefficient of semiconductors described within the two-band Kane model in the presence of an external electric field for photon energy below and above the semiconductor band gap. The optical matrix element depends on the momentum vector, and this important aspect has been incorporated in the present analysis. For photon energies below the band gap, the absorption coefficient exhibits an exponential falloff with the electric field and the photon energy. For the opposite inequality, the same coefficient oscillates with the photon energy without consideration of the Wannier–Stark levels, which generally exists in a band due to the presence of an external electric field. Additional oscillations are expected in the above two cases because of the formation of the discrete Stark ladders.

Optical absorption coefficient of semiconductors in the extrinsic region obtained by photoconductivity measurements: application to SI GaAs

A simple method for measurements of optical absorption coefficient in the extrinsic region of semiconductors is suggested and demonstrated for photoionisation as well as intracentre transitions using standard semi-insulating GaAs and GaAs:V wafers. Also discussed is its applicability to inhomogeneous compound semiconductors.

Multiphoton absorption by charge carriers in semiconductors in a magnetic field

AbstractA theory of absorption of strong electromagnetic radiation by charge carriers in semiconductors in a static uniform magnetic field is developed. By using the density matrix method in path‐integral representation the multiphonon absorption coefficient in semiconductors is calculated at arbitrary temperatures for different scattering mechanisms such as ionized impurities, polar and nonpolar interactions with optical phonons, and deformation and piezoelectric interactions with acoustical phonons. The coefficients of magnetic non‐linearity in weak magnetic fields are studied. The structure of the absorption spectrum in an arbitrary magnetic field is investigated, the existence of multiphoton absorption resonances revealed and the dependence of their parameters on the order of resonance and on the conditions of absorption is obtained. The asymptotic properties of the absorption coefficient in a strong magnetic field are analyzed. The anisotropy of absorption due to a magnetic field is discussed in each case.

Excitonic absorption coefficient in semiconductors

AbstractA criticism of Elliott's model of the excitonic absorption coefficient has been made in a recent paper by Auvergne and Camassel. They proposed a model in which the electron‐hole interaction is neglected for the continuum states. This criticism was based mainly on an alleged discontinuity in the exciton envelope function between the discrete and continuum spectra. In the present paper it is shown that in fact, no such discontinuity exists and the electron‐hole interaction should not be ignored in the continuum. Elliott's model is correct within the specified limitations and, appropriately broadened, gives quite satisfactory agreement with the experimental data.

9B9 - The theory of semiconductor lasers with consideration of saturation effects

Semiconductor behavior in strong fields having a frequency close to the absorption band is considered. It is proved that only the slowing down and recombination times of four different relaxation times are of importance for weaker fields. In this case, equality of Fermi-level electron and hole quasi-levels to light quantum energy corresponds to a saturation condition. A semiconductor absorption coefficient regarding saturation is calculated.

Saturation of interband transitions in semiconductors

Summary form only, as given. Semiconductor behavior in strong fields having a frequency close to the absorption band is considered. It is proved that only the slowing down and recombination times of four different relaxation times are of importance for weaker fields. In this case, equality of Fermi-level electron and hole quasi-levels to light quantum energy corresponds to a saturation condition. A semiconductor absorption coefficient regarding saturation is calculated.