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Potential well
About: Potential well is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 30812 citations.
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TL;DR: In this paper, an analysis of the dependence of the nonradiative-decay rates on carrier confinement in terms of an escape of carriers from the confined zone by tunnelling through silicon oxide barriers is presented.
Abstract: Among the various nanometer-sized silicon structures, high porosity anodically oxidized porous silicon has many interesting properties. Luminescence quantum efficiency as high as 3% at room temperature and luminescence decay rates as long as several hundreds of microseconds show that both radiative and nonradiative processes have low efficiencies. An analysis of the dependence of the nonradiative-decay rates on carrier confinement in terms of an escape of carriers from the confined zone by tunnelling through silicon oxide barriers accounts for our experimental results with an average barrier thickness of 3 nm. The same model is extended and explains the luminescence decay shapes and the electroluminescence signal.
30 citations
TL;DR: In this paper, a co-precipitation method was used to produce Zn1−xMgxS (x = 0, 0.2 and 0.4) quantum dots, which had three emission bands in the UV and visible regions corresponding to near band edge emission and defect related emissions.
30 citations
TL;DR: In this article, thin films of GaAs were electrochemically prepared from acidic solutions of pure metallic Ga and As 2 O 3, and structural characterization of the nanoparticles were carried out by XRD technique which exhibits partial amorphization of the crystallites in the low electrolysis current regime.
30 citations
TL;DR: In this paper, a diode based on nanocrystalline silicon (nc-Si) exhibits characteristic quasi-ballistic emission effects in various media, such as air and Xe ambient, which can be used for parallel electron beam lithography and high-sensitivity image-pickup.
Abstract: A quantum confinement effect renders silicon a functional wide-gap material with useful functions. For instance, a diode based on nanocrystalline silicon (nc-Si) exhibits characteristic quasi-ballistic emission effects in various media. As means for physical excitation and probing, the applicability to parallel electron beam lithography and high-sensitivity image-pickup has been demonstrated in vacuum. The energetic electron incidence into air and Xe ambient induces negative ion generation by electron attachment into oxygen molecules and vacuum ultraviolet light emission by internal excitation of Xe molecules, respectively. Another effect is that the nc-Si ballistic emitter can supply highly reducing electrons into aqueous and metal-salt solutions without the use of counter electrodes. This is an attractive process that will be applicable to hydrogen generation and thin metal film deposition.
29 citations
TL;DR: The nanocones formed on the irradiated surface of semiconductors by Nd:YAG laser possessing the properties of 1D graded bandgap have been found for Si, Ge, and SiGe as well, however QD structure in CdTe was observed.
Abstract: On the basis of the analysis of experimental results, a two-stage mechanism of nanocones formation on the irradiated surface of semiconductors by Nd:YAG laser is proposed for elementary semiconductors and solid solutions, such as Si, Ge, SiGe, and CdZnTe. Properties observed are explained in the frame of quantum confinement effect. The first stage of the mechanism is characterized by the formation of a thin strained top layer, due to redistribution of point defects in temperature-gradient field induced by laser radiation. The second stage is characterized by mechanical plastic deformation of the stained top layer leading to arising of nanocones, due to selective laser absorption of the top layer. The nanocones formed on the irradiated surface of semiconductors by Nd:YAG laser possessing the properties of 1D graded bandgap have been found for Si, Ge, and SiGe as well, however QD structure in CdTe was observed. The model is confirmed by "blue shift" of bands in photoluminescence spectrum, "red shift" of longitudinal optical line in Raman back scattering spectrum of Ge crystal, appearance of Ge phase in SiGe solid solution after irradiation by the laser at intensity 20 MW/cm2, and non-monotonous dependence of Si crystal micro-hardness as function of the laser intensity.
29 citations