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Cathodoluminescence Contrast Of Localized Defects Part I. Numerical Model For Simulation, K. L. Pey, D. S. H. Chan, J. C. H. Phang

Scanning Microscopy

A three-dimensional model has been developed for cathodoluminescence contrast of localized defects in semiconductors. The numerical model incorporates electron-solid interaction effects, charge transport phenomena and optical losses. Electron-solid interaction is modelled by a Monte Carlo method. Three-dimensional continuity equation and derivative boundary conditions are discretized by a central-difference quotients scheme. Localized defects are represented by regions of enhanced non-radiative recombination. The discretized linear difference equations of the boundary value problem are solved by the successive-over-relaxation method. A method for avoiding the divergence problem during the successive-over-relaxation calculation is illustrated. The solutions of the model are compared with the analytical results …

Cathodoluminescence Contrast Of Localized Defects Part Ii. Defect Investigation, K. L. Pey, J. C. H. Phang, D. S. H. Chan

Scanning Microscopy

Cathodoluminescence contrast from defects with different geometrical and electronic properties have been studied using the numerical model developed in Part I. The contrast of a localized subsurface defect exhibits a maxima at a specific beam energy E_max which corresponds to the depth of the defect. The contrast of a dis-location which intersects the top surface perpendicularly is a decreasing function of beam energy. The differences in the image profiles of the two different kinds of defects allow the two types of imperfections to be distinguished. In addition, the resolution of a subsurface defect at beam energies lower than E …

Luminescence Spectroscopy Of Semiconductor Surfaces And Interfaces, L. J. Brillson, S. Chang, A. D. Raisanen, I. M. Vitomirov

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Low energy cathodoluminescence spectroscopy (CLS) employing incident electron energies in the range of a few kV or less enable measurement of electronic structure near semiconductor surfaces and interfaces. Coupled with photoluminescence spectroscopy (PL), the CLS technique has been extended to characterize electronic structure tens of nanometers below the free surface at metal-semiconductor and semiconductor-semiconductor junctions. CLS has revealed discrete, deep electronic states for clean and metallized semiconductor surfaces as a function of atomic ordering as well as vicinal surfaces as a function of misorientation. A combination of CLS and PL reveals deep level features associated with strain relaxation and dislocations …

Luminescence From Porous Silicon, Yasunori Mochizuki

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Structural and optical properties of porous Si are reviewed with the main emphasis on the radiative recombination mechanisms. Behaviors of the visible photoluminescence and another intense luminescence process (the infrared luminescence) are discussed based on the available data provided by photoluminescence and related techniques. It is demonstrated that a further insight into the interrelation of these luminescence processes can be obtained by the optically-detected magnetic resonance method, in which non-radiative point defects (surface dangling bonds) are used as a local structural probe for the radiative states.

As for the model for the visible light emission, the implication of the quantum …

Diamond Luminescence, R. Heiderhoff, L. J. Balk

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Luminescence spectroscopy is an established tool to investigate natural, high pressure synthesized, and chemical vapour deposited (CVD) diamond. The spectral range extends from 5.3 eV in the ultraviolet to approximately 1.2 eV in the near-infrared. More than 100 optical centres have been observed.

Since the early 1930's, semiconducting diamond for electronic devices has been of interest to science. The large bandgap (5.5 eV), low dielectric constant (5.7), and high thermal conductivity (about 5 times larger then that of Ag), as well as the superior charge-carrier transport properties, such as electron and hole mobility (µ^-: 2200 cm²/Vs, …

Advances In Research Of Defects In Quartz Based On Luminescence, A. Halperin

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The first part of this paper reviews the observation of the unconventional thermoluminescence {TL(M), where M = Li or Na} peaks observed in the glow curve of Li-and Na-containing quartz, and describes the full solution of the puzzling effect of the TL(M) peaks which needed a two irradiation procedure for their formation. Of interest is the intermediate warming (IW) method, which consisted of two irradiations and warming of the sample to 150-300 K between the two irradiations. This was explained as follows: the first low temperature irradiation produces {AlO₄/M/h}⁺ centers, when the now loosely bound M ions …