Potential well

About: Potential well is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 30812 citations.

Influence of different types of substrates on the physical properties of CdSe films

Abstract: Cadmium Selenide, CdSe, thin films deposited on different substrate types; FTO/glass,/glass, and ITO/glass substrates were produced by thermal evaporation method in the room temperature The influence of different types of substrates on the structural, optical and electrical properties of the films was studied by X-ray diffraction and absorption photo spectroscopy respectively X-ray diffractions revealed that all the CdSe films have a polycrystalline with cubic structure having preferred orientation (111) at 2θ ≈ 251° The optical energy band, Eg, values support the fact that the films have semiconductor behavior which can be attributed to the quantum confinement effect It was observed that the optical properties such as transmittance, reflectance, optical bandgap, and refractive index and some another parameters of CdSe films were strongly affected by types of substrates The electrical properties were measured at room temperature using two probe methods

Fabrication of luminescent silver doped PbS nanowires in polymer.

Abstract: We report here fabrication of silver (0 to 1.76 mol%) doped PbS nanowires (radius r approximately 1.75 nm) in polymer by a simple wet chemical process. An X-ray photoelectron spectroscopy study clearly confirms the possibility of silver (Ag) doping in PbS nanowires. Both absorption and photoluminescence spectra reveal very strong quantum confinement effect in PbS nanowires as expected for a r/Bohr radius ratio approximately 0.0972 nm. Visible excitonic emission is observed at room temperature in the photoluminescence spectra of undoped and silver doped PbS nanowires in polymer. The excitonic emission is appreciably blue-shifted when doped by silver (1.76 mol%) indicating strong modification of the electronic states by magnetic silver ions. While Ag2+ centers at the substitutional lattice site show an emission band around 525 nm, Ag0 at the interstitial site act as nonradiative recombination centers. Effect of silver doping on the luminescence intensity is also discussed.

High peak-to-valley current ratio GaAs/InGaAs/InAs double stepped quantum well resonant interband tunneling diodes at room temperature

Abstract: A high ratio of the peak current density to the valley current density of current-voltage characteristic is accomplished for the double stepped quantum well resonant interband tunneling diode (DSQW RITD). Results for good quantum confinement effect and long drift layer with deep quantum well GaAs/In0.59Ga0.41As/InAs DSQW RITD that has a lower valley current density of about 0.98 A/cm2 and a higher peak-to-valley current ratio (PVCR) reached 622 at room temperature than conventionally designed double quantum well resonant interband tunneling diodes (DQW RITDs) are presented. This PVCR value is also the highest value than those of the other resonant tunneling diodes.

Quantum confinement induced ultra-high intensity interfacial radiative recombination in nanolaminates

Abstract: Al2O3/ZnO, Al2O3/TiO2, TiO2/ZnO and MgO/ZnO nanolaminates (NLs) were prepared using atomic layer deposition to explore the dependence of luminescence characterization on the sublayer width and constituents When the ZnO sublayer width is larger than the Bohr radius in Al2O3/ZnO NLs, the UV luminescence arising from ZnO is reduced and even quenched with decreasing the ZnO width due to the nonradiative recombination (NR) caused by the existence of interface states, while for the ZnO width smaller than the Bohr radius, a visible luminescence rather than UV emission is observed and further enhanced with decreasing the ZnO width It is also found that the visible luminescence needs a certain width of Al2O3 and is extinguished by the replacement of Al2O3 with TiO2 A theoretical model based on the configuration coordination and quantum confinement effect is proposed to understand the physical origin underlying the intriguing optical behaviour The mechanism has generality and is applicable for other NLs as well, such as Al2O3/TiO2 and MgO/ZnO NLs with ultra-thin sublayers in which similar luminescence enhancements are also observed This work may provide a promising approach for realizing high performance luminescence with various wavelengths for electro- and photo-luminescence applications in NLs