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Mechanisms and influence factors of surface optical (SO) phonon-mode-assisted exciton photoluminescence (PL) spectroscopy in quasi-1-dimensional (Q1D) nitride nanostructures remain a subject of debate. In this work, using momentum and energy conservation laws, a constraint relationship for the frequency and wave number of SO phonon-mode-assisted exciton PL is established. Using the dispersion relationships of SO modes in anisotropic wurtzite nanowires, the frequency and wave number of SO-mode-assisted exciton PL emission are determined. The present theoretical scheme and numerical results not only explain a current experimental discrepancy but could also be used to predict and design exciton PL spectroscopy with SO phonon modes in Q1D nanostructures. [ABSTRACT FROM AUTHOR]

Room temperature ferromagnetic Zn0.95Co0.05O thin films with (002) preferential orientation have been successfully deposited by pulsed laser deposition at different oxygen partial pressures on n-type (100) silicon substrate. A maximum saturation magnetization of 0.86 μB/Co was achieved at room temperature at 5 × 10-6 Torr oxygen partial pressure. HRTEM and XPS results indicate that the observed ferromagnetism is not due to metallic Co microclusters in the thin films. Oxygen vacancies in the films were detected from photoluminance characterization, which showed a significant effect on the ferromagnetic behavior. By changing the amount of oxygen vacancies through adjusting the oxygen partial pressure during deposition and post-deposition annealing, the ferromagnetic behavior of the thin films can be tuned significantly. This implies that the oxygen vacancies, which contribute to the bound magnetic polarons model and RKKY indirect interaction, are the likely cause of this ferromagnetism. [ABSTRACT FROM AUTHOR]

Visible and infrared photoluminescence was observed from AlN:Er films grown by reactive radio-frequency magnetron sputtering under different powers. X-ray diffraction indicates that the films have a c-axis oriented hexagonal wurtzite structure with an average crystallite size of about 59–83 nm and a strain of about (1.12–1.69)×10-3. Green emissions (∼540 and 558 nm) from the AlN:Er films are due to the intra-4fn transition of Er3+ from 2H11/2 and 4S3/2 to 4I15/2, and infrared (∼1535 nm) emissions correspond to 4I13/2 to 4I15/2 transitions. Increasing the sputtering power results in larger grain size, lower strain, and enhancement of the luminescence intensity. [ABSTRACT FROM AUTHOR]

Presents a detailed characterization of the ordered structure in silicon-doped Ga[sub0.51]In[sub0.49]P. Influence of silicon doping on the ordering in GaInP layers; Analysis of undoped layers grown at various substrate temperatures; Relationships between photoluminescence peak energy and electron concentration of silicon-doped samples at room temperature.

Focuses on a study which presented a photoluminescence (PL) analysis of gallium indium phosphide/gallium arsenide single-quantum well structures grown by metal-organic vapor-phase epitaxy. Description of the sample and procedure; Estimation of the growth temperature dependent conduction and valence band discontinuity of the heterojunction; Results of x-ray diffraction measurements and simulations.

Presents a study that investigated gallium compound interfaces grown by low-pressure metalorganic vapor phase epitaxy at various temperatures and in different structures. Use of photoluminescence method; Results of the examination on gallium compound using x-ray diffraction measurements and simulations with dynamical theory.

The effects of MoO3 molecular doping in poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate) (PEDOT:PSS) on the chemical structure and, in turn, on the carrier collection efficiency of c-Si/PEDOT:PSS heterojunction solar cells are demonstrated. Scanning electron microscopy revealed that the hydrophilic PSS polymer chain was intercalated into the interlayer van der Waals gap of MoO3 flake sheets, which modified the chemical structure of PEDOT:PSS. MoO3 exhibited intense photoluminescence in the 350-550 nm region, which enhanced the carrier collection efficiency of c-Si/PEDOT:PSS heterojunction solar cells with no significant changes. These findings suggest that the intense photoluminescence of MoO3 and its light wavelength conversion contribute to the increased carrier collection efficiency. [ABSTRACT FROM AUTHOR]

The effect of growth temperature on morphology, structure, and photoluminescence (PL) of Eu-doped GaN (GaN:Eu) films grown by magnetron sputtering, and the relationships of growth-temperature-structure-PL were investigated by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and PL. The films grown at room temperature (RT), 573 K, and 773 K are composed of random crystalline grains, c-oriented GaN nanorods with lots of stacking faults, and well-crystalline c-oriented GaN, respectively. The characteristic emission lines of the Eu3+ were observed in the PL spectra at room temperature for the 573-K-grown and 773-K-grown films, while no emission line for the RT-grown film. The PL intensity from the 773-K-grown film is much stronger than that from the 573-K-grown film. [ABSTRACT FROM AUTHOR]

Visible light emission has been obtained at room temperature by photoluminescence (PL) and cathodoluminescence (CL) from Tb-doped B[sub 2]N[sub 2]CO thin films prepared by radio-frequency magnetron sputtering. The films were deposited by sputtering TbB[sub n] (n = 4, 6, 12, 25, and 50) targets in an atmosphere of Ar and N[sub 2] gas mixture. The films are uniformly composed of very small particles with particle size of about 20-40 nm, which consist of turbostratic BN phase and amorphous phase. The characteristic PL peaks are observed in the spectral range from 300 to 800 nm, and correspond to the two groups of transitions of Tb[sub 3+] ions: [sup 5]D[sub 3]→[sup 7]F[sub J] (J=6, 5, 3) and &sup5;D[sub 4]→[sup 7]F[sub J] (J= 6, 5, 4, 3). The strongest PL peak at ∼547.2 nm is about four times greater than the other signals in the investigated range, indicating that the films have strong green light emission. CL intensity is very weakly dependent on the temperature. [ABSTRACT FROM AUTHOR]