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PL Peak (pl + peak)
Selected AbstractsStructural and photoluminescence studies of erbium-implanted nanocrystalline silicon thin filmsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 9 2009M. F. Cerqueira Abstract Hydrogenated amorphous and nanocrystalline silicon thin films deposited by hot wire (HW) and radio-frequency plasma-enhanced chemical vapour deposition (RF-PECVD) were erbium-implanted. Their pre-implantation structural properties and post-implantation optical properties were studied and correlated. After 1,h annealing at 150,°C in nitrogen atmosphere only amorphous films showed photoluminescence (PL) activity at 1.54,µm, measured at 5,K. After further annealing at 300,°C for 1,h, all the samples exhibited a sharp PL peak positioned at 1.54,µm, with an FWHM of ,5,nm. Amorphous films deposited by HW originated a stronger PL peak than corresponding films deposited by RF, while in nanocrystalline films PL emission was much stronger in samples deposited by RF than by HW. There was no noticeable difference in Er3+ PL activity between films implanted with 1,×,1014 and 5,×,1015,atoms,cm,2 Er doses. [source] RF-MBE growth of InN on 4H-SiC (0001) with off-anglesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7-8 2010Misao Orihara Abstract We have grown InN on 4H-SiC (0001) substrates with various off-angles by RF-N2 plasma molecular beam epitaxy (RF-MBE). Scanning electron microscope observation revealed that InN films grown on 4H-SiC (0001) substrates with off-angles of 4° and 8° are very smooth and that there are no voids which have often observed for InN epitaxial layers. X-ray diffraction reciprocal space maps for InN grown on 4H-SiC (0001) showed that the c-axes of InN grown on 4H-SiC 4° and 8° off substrates are inclined by 0.35° and 0.8°, respectively, toward the misorientation of the substrate while the c-axis of InN is parallel to that of 4H-SiC for the on-axis substrate. Strong PL peak was observed from InN grown on 4° off substrate at 0.68 eV at 15 K. The PL peak was clearly observed even at room temperature and simply shifted to lower energies with increasing temperature. The difference in the PL peak energy between at 15 K and 300 K was 20 meV, which is reasonable taking into account the difference in the thermal coefficients of InN and SiC (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Photoluminescence of cubic InN films on MgO (001) substratesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2008T. Inoue Abstract We have studied photoluminescence from cubic InN films grown on MgO substrates with a cubic GaN underlayer by RF N2 plasma molecular beam epitaxy. A single PL peak was observed at 0.47 eV. By analyzing the reflectance spectra of cubic InN films, we could derive the refractive index and extinction coefficient, and found the band gap energy of cubic InN is 0.48 eV, indicating that the PL peak observed at 0.47 eV is due to the interband transition of cubic InN. The difference in the PL peak energy between hexagonal and cubic InN is in good agreement with that predicted by ab-initio calculations. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structural and optical properties of polycrystalline MgxZn1,xO and ZnO:Mn films prepared by chemical spray pyrolysisPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 8 2006Tomoaki Terasako Abstract Polycrystalline MgxZn1,xO (0.00 , x , 0.21) and ZnO:Mn films prepared by chemical spray pyrolysis were characterized by X-ray diffraction, optical transmittance, photoacoustic (PA) spectroscopy and photoluminescence (PL). Successful growth of the MgxZn1,xO (0.00 , x , 0.21) films was confirmed by the blue shift of both the near-band-edge PL peak and absorption edge with increasing the alloy composition x. However, the influence of the tail states caused by the deviation from stoichiometric compsosition and/or the spatial fluctuation of the alloy composition x was observed on the PA and PL spectra. Both the transmittance and PA spectra for the ZnO:Mn films showed the absorption band due to the d-d transitions in Mn2+ ion. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Photoluminescence from Boron-Doped Titanium Nitride Nanocomposite Thin Films Prepared by the Magnetron Sputtering MethodJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2007Sheng-Guo Lu Boron-doped titanium nitride (TiBN) thin films with nanosized grains were prepared by a magnetron sputtering method. X-ray diffraction and transmission electron microscopy observation indicated that TiBN thin films have a cubic structure with grains ,5 nm in size. The photoluminescence (PL) of the films was investigated as a function of temperature over a wavelength range of 350,900 nm. Two PL peaks near 3.20 and 2.38 eV were conisdered to have resulted from the recombination of the donor-bound excitons and deep-trap defects with the holes in the valence band, respectively. An energy transfer from bound electrons to deep-trap defects was observed in the nanocomposite thin film. [source] Photoluminescence properties of GaAs nanowire ensembles with zincblende and wurtzite crystal structurePHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 7 2010B. V. Novikov Abstract Self-standing III,V nanowires (NWs) are promising building blocks for future optoelectronic devices such as LEDs, lasers, photodetectors and solar cells. In this work, we present the results of low temperature photoluminescence (PL) characterization of GaAs NWs grown by Au-assisted molecular beam epitaxy (MBE), coupled with the transmission electron microscopy (TEM) structural analysis. PL spectra contain exci- ton peaks from zincblende (ZB) and wurtzite (WZ) crystal structures of GaAs. The peaks are influenced by the quantum confinement effects. PL bands corresponding to the exciton emission from ZB and WZ crystal phases are identified, relating to the PL peaks at 1.519 eV and 1.478 eV, respectively. The obtained red shift of 41 meV for WZ GaAs should persist in thin NWs as well as in bulk materials. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Optical and magnetic properties of the DyN/GaN superlatticePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003Y. K. Zhou Abstract Ferromagnet/semiconductor DyN/GaN superlattice structures were grown on SiC substrate by radio frequency molecular beam epitaxy. Formation of DyN was confirmed by X-ray diffraction measurements. The temperature dependence of the photoluminescence (PL) spectra for the DyN/GaN superlattice and GaDyN samples was studied. Sharp PL peaks from two samples showed no shift with temperature, indicating the intra-atomic f,f transition at Dy ions. Comparison of the PL spectra for the DyN/GaN superlattice and GaDyN suggests that GaDyN is formed at the GaN/DyN interface. The DyN/GaN superlattice exhibited two ferromagnetic components; one is major at low temperatures (<50 K) and the other is major at high temperatures (>350 K). The former shows large coercivity Hc of about 1800 Oe at 7 K, which was originated from DyN layers. The latter may come from GaDyN, which was formed at the GaN/DyN interface. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Structural and optical properties of ZnSe-based diluted magnetic semiconductor quantum-well wire arrays by wet chemical etchingPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2010Tsutomu Muranaka Abstract The ZnSe-based mesa structures with well-defined and smooth facets were successfully demonstrated by using molecular beam epitaxy (MBE) and wet chemical etching. The ZnSe structures were found to be bound by (111) and (-1-11) facets along the [-110] direction, and bound by (1-11) and (-111) facets along the [110] direction, respectively. The intensities of the non-polarized PL peaks from the [-110]- and [110]-oriented QWW structures were almost proportional to the unetched region and additional decreases were not observed. The PL peaks from the QWW structures were found to be highly polarized when the polarization angle was aligned parallel to the wire direction. The degrees of the linear polarization were 18% for the [-110]-oriented QWW structure and 26% for the [-110]-oriented QWW structure, respectively. The results of the PL and magneto-PL measurements show no process-induced damage to degrade magneto-optical performance of the DMS structures by using this method. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Photoluminescence depth-profiling of lattice-mismatched InGaN thick film on GaN using inductively coupled plasma etchingPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006Ji-Myon Lee Abstract Photoluminescence depth profiling of highly strained In0.1Ga0.9N and In0.15Ga0.85N epitaxial films have been studied employing an inductively coupled Cl2 plasma etching. The photoluminescence measurements showed that thick InGaN films (0.2 ,m) consist of three different structural phases; (i) an InN-rich region near the InGaN film surface, (ii) a region that was free from InN-rich phase under stress-relaxation in the middle of the film, and (iii) an InGaN/GaN interface region. In region (i), a higher wavelength peak from the InN-rich phase was dominant. After removing the surface layer of 500 Å, the PL peaks from InN-rich phases completely disappeared, suggesting that the InN-rich phase region is confined to a depth of 500 Å. In regions of (ii) and (iii), the strain-relaxation between InGaN and GaN had a significant influence on the luminescence properties of InGaN. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||