This work reports on theoretical and experimental investigation of the impact of InAs quantum dots (QDs) position with respect to InGaAs strain reducing layer (SRL). The investigated samples are grown by molecular beam epitaxy and characterized by photoluminescence spectroscopy (PL). The QDs optical transition energies have been calculated by solving the three dimensional Schrödinger equation u...

In this work, we have studied the dependence of the size and luminescence of self-assembled InAs quantum dots (SAQDs) on the growth conditions. The SAQDs were grown on GaAs (1 0 0) substrates by molecular beam epitaxy (MBE). Their structural and optical properties were studied by atomic force microscopy (AFM), and photoluminescence spectroscopy (PL). The growth of the InAs SAQDs was in situ mon...

ZnO films were prepared on p-Si (111) substrates by using atomic layer deposition. High-resolution x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and I-V measurements were carried out to characterize structural, electrical, and optical properties. After introducing a 60-nm-thick AlN buffer layer, the growth direction ...

The characteristics of multi-layered InAs/GaAs self assembled quantum dots (SAQDs) annealed after the growth were here studied using a combination of capacitance-voltage (C-V) measurements, Raman scattering and photoluminescence (PL) spectroscopy. The combination of the results obtained with the three techniques, gave evidences that the annealing at 500oC causes the sharpness of the SAQDs inter...

Low temperature photoluminescence (PL) spectroscopy was used to evaluate CdTe single crystals grown by a vertical gradient freeze method. Materials suitable for xray detectors preparation were in the center of attention. Both usual above-gap-excitation and rarely used below-gap-excitation was employed to investigate native defects and impurities. Tunable Ti-sapphire laser was applied to study e...

Graphene oxide (GO) is a graphene sheet modified with oxygen functional groups in the form of epoxy and hydroxy groups on the basal plane and various other types at the edges. It exhibits interesting steady-state photoluminescence (PL) properties. For example, low-energy fluorescence in red to near infrared (NIR) wavelengths (from 600– 1100 nm) has been detected for suspensions and solid thin f...

In this study, novel carbohydrate-based nanoconjugates combining chemically modified chitosan with semiconductor quantum dots (QDs) were designed and synthesised via single-step aqueous route at room temperature. Glycol chitosan (G-CHI) was used as the capping ligand aiming to improve the water solubility of the nanoconjugates to produce stable and biocompatible colloidal systems. UV-visible (U...

The CdSe nanocrystals (NCs) have been synthesized by hot-injection method to improve the crystallinity of synthesized nanoparticles and reconstruct the surface of nanoparticles. The crystalline structure and optical properties of these NCs are characterized by X-ray powder diffraction (XRD), ultraviolet–visible light absorption and photoluminescence (PL) spectroscopy. The CdSe NC grains are rou...

Zinc Sulphide particle in the nanometer size regime has been synthesized using chemical routes. The particles were capped using 2-mercaptoethanol to achieve the stability and avoid the coalescence. The as-obtained particles were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–VIS absorption and photoluminescence (PL) spectra. The dielectric measurements of t...

Band gap-tunable potassium doped graphitic carbon nitride with enhanced mineralization ability was prepared using dicyandiamide monomer and potassium hydrate as precursors. X-ray diffraction (XRD), N2 adsorption, UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) were used to...