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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 article, the authors reported on the Raman blue shift of layered MoS2 films as well as an anomalous blue shift in the photoluminescence spectra of nanocrystallite MoS 2 films.
16 citations
TL;DR: In this article, the spontaneous polarization, the valence band offset, and the quantum confinement effect for thin SiC and AlN cubic/hexagonal heterocrystalline superlattices were studied by use of a full potential linear muffin-tin orbital method (FP-LMTO).
Abstract: The spontaneous polarization, the valence band offset, and the quantum confinement effect for thin SiC and AlN cubic/hexagonal heterocrystalline superlattices are studied by use of a full potential linear muffin-tin orbital method (FP-LMTO). We find that the polarization is screened and suppressed while the length of the cubic region grows. The band offsets do not change with layer thickness. For thin superlattices, the quantum confinement effects dominate and result in a band gap which stays larger than the gap of the bulk cubic structure. Furthermore, the energy levels of the bound states in the quantum well resemble the pattern of the energy levels of conventional III-V based quantum wells and superlattices but at a much smaller length scale, which is due to the higher quantum well depth and the larger effective masses in SiC and AlN systems.
16 citations
TL;DR: According to the measurements and numerical simulation results, the strain relaxation effect is believed to play a dominant role rather than the quantum confinement effect in determining the emission wavelength of nanopillars.
Abstract: Nanopillars with diameters down to 20 nm were fabricated from InGaN/GaN multiple quantum wells (MQWs) by using a nanosphere–SiO2 double mask and inductively coupled plasma (ICP) etching. Clear photoluminescence (PL) signals of the nanopillars were observed at room temperature, and the PL peak energy at 20 K showed a large blueshift of 220 meV compared with that of the original MQWs. The exciton activation energy in the temperature range of 100 ∼300 K increased from 33 meV for MQWs to 83 meV for nanopillars. According to the measurements and numerical simulation results, the strain relaxation effect is believed to play a dominant role rather than the quantum confinement effect in determining the emission wavelength of nanopillars. This work also demonstrates a promising method for obtaining IIInitride quantum dots.
16 citations
TL;DR: In this article, the authors compared pure and hydrogen terminated silicon carbide (SiC) nanowires with ab initio density functional theory calculations and showed that the pure wires preserve their crystalline-like topology with only small relaxations on their surface.
Abstract: Pure and hydrogen terminated silicon carbide (SiC) nanowires grown along [0001] direction in the wurtzite structure are studied using ab initio density functional theory calculations. The pure wires preserve their crystalline-like topology with only small relaxations on their surface. Also, the pure wires are semiconducting, but their band gap energy decreases with decreasing diameter due to the presence of surface states. As expected, hydrogen saturation induces a broadening of the band gap energy because of the quantum confinement effect. SiC nanowires are also predicted to be very rigid. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
16 citations
Journal Article•
TL;DR: The influence of varying etching time in the anodizing solution on structural and optical properties of porous silicon has been investigated in this article, where it is observed that pore size increases with the etch time and reaches maximum for 20 minutes and then decreases.
Abstract: Porous silicon layers have been prepared from n-type silicon wafers of (100) orientation. SEM, FTIR and PL have been used to characterize the morphological and optical properties of porous silicon. The influence of varying etching time in the anodizing solution, on structural and optical properties of porous silicon has been investigated. It is observed that pore size increases with etching time and attain maximum for 20 minutes and then decreases. The PL spectrum peak shifts towards the higher energy side, which supports the quantum confinement effect in porous silicon. The FTIR shows that the Si-Hn peaks are observed at the surface of the PS layer and these chemical species also give raise the PL in PS.
16 citations