Influence of the Annealing Ambient on Structural and Optical Properties of Rare Earth Implanted GaN

2005 ◽  
Vol 892 ◽  
Author(s):  
Katharina Lorenz ◽  
E. Nogales ◽  
R. Nédélec ◽  
J. Penner ◽  
R. Vianden ◽  
...  

AbstractGaN films were implanted with Er and Eu ions and rapid thermal annealing was performed at 1000, 1100 and 1200 °C in vacuum, in flowing nitrogen gas or a mixture of NH3 and N2. Rutherford backscattering spectrometry in the channeling mode was used to study the evolution of damage introduction and recovery in the Ga sublattice and to monitor the rare earth profiles after annealing. The surface morphology of the samples was analyzed by scanning electron microscopy and the optical properties by room temperature cathodoluminescence (CL). Samples annealed in vacuum and N2 already show the first signs of surface dissociation at 1000 °C. At higher temperature, Ga droplets form at the surface. However, samples annealed in NH3 + N2 exhibit a very good recovery of the lattice along with a smooth surface. These samples also show the strongest CL intensity for the rare earth related emissions in the green (for Er) and red (for Eu). After annealing at 1200 °C in NH3+N2 the Eu implanted sample reveals the channeling qualities of an unimplanted sample and a strong increase of CL intensity is observed.

2000 ◽  
Vol 650 ◽  
Author(s):  
Eduardo J. Alves ◽  
C. Liu ◽  
Maria F. da Silva ◽  
José C. Soares ◽  
Rosário Correia ◽  
...  

ABSTRACTIn this work we report the structural and optical properties of ion implanted GaN. Potential acceptors such as Ca and Er were used as dopants. Ion implantation was carried out with the substrate at room temperature and 550 °C, respectively. The lattice site location of the dopants was studied by Rutherford backscattering/channeling combined with particle induced X-ray emission. Angular scans along both [0001] and [1011] directions show that 50% of the Er ions implanted at 550 oC occupy substitutional or near substitutional Ga sites after annealing. For Ca we found only a fraction of 30% located in displaced Ga sites along the [0001] direction. The optical properties of the ion implanted GaN films have been studied by photoluminescence measurements. Er- related luminescence near 1.54 μm is observed under below band gap excitation at liquid helium temperature. The spectra of the annealed samples consist of multiline structures with the sharpest lines found in GaN until now. The green and red emissions were also observed in the Er doped samples after annealing.


1962 ◽  
Vol 3 (3) ◽  
pp. 323-325 ◽  
Author(s):  
S. S. Batsanov ◽  
G. N. Grigor'eva ◽  
N. P. Sokolova

1968 ◽  
Vol 8 (3) ◽  
pp. 410-414 ◽  
Author(s):  
E. D. Ruchkin ◽  
M. N. Sokolova ◽  
S. S. Batsanov

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2110
Author(s):  
Olga Yu. Koval ◽  
Vladimir V. Fedorov ◽  
Alexey D. Bolshakov ◽  
Sergey V. Fedina ◽  
Fedor M. Kochetkov ◽  
...  

Controlled growth of heterostructured nanowires and mechanisms of their formation have been actively studied during the last decades due to perspectives of their implementation. Here, we report on the self-catalyzed growth of axially heterostructured GaPN/GaP nanowires on Si(111) by plasma-assisted molecular beam epitaxy. Nanowire composition and structural properties were examined by means of Raman microspectroscopy and transmission electron microscopy. To study the optical properties of the synthesized nanoheterostructures, the nanowire array was embedded into the silicone rubber membrane and further released from the growth substrate. The reported approach allows us to study the nanowire optical properties avoiding the response from the parasitically grown island layer. Photoluminescence and Raman studies reveal different nitrogen content in nanowires and parasitic island layer. The effect is discussed in terms of the difference in vapor solid and vapor liquid solid growth mechanisms. Photoluminescence studies at low temperature (5K) demonstrate the transition to the quasi-direct gap in the nanowires typical for diluted nitrides with low N-content. The bright room temperature photoluminescent response demonstrates the potential application of nanowire/polymer matrix in flexible optoelectronic devices.


2019 ◽  
Vol 33 (05) ◽  
pp. 1950024 ◽  
Author(s):  
Fatma Meydaneri Tezel ◽  
İ. Afşin Kariper

In this study, zinc selenide (ZnSe) thin films were produced on glass substrate by using chemical bath deposition (CBD) method at 80[Formula: see text]C, from aqueous solutions of zinc sulphate and sodium selenosulphide, which were produced using solid selenium as the selenium source. The optical and structural properties of ZnSe thin films were investigated at room-temperature. The pH of the chemical bath, in which ZnSe thin films were immersed, were changed between pH:8–11. Optical properties of the films, including extinction coefficient, refractive index, reflectance, absorbance, transmittance, dielectric constants and optical density values were calculated using absorbance and transmittance measurements determined using a Hach Lange 500 spectrophotometer, in 300–1100 nm wavelength range. Optical bandgap values were obtained from transmittance and absorbance spectra ranged between 2.12 and 2.49 eV. According to XRD results, it was found that the films have polycrystalline structure and they exhibited different film thicknesses depending on phase and pH changes.


2014 ◽  
Vol 912-914 ◽  
pp. 325-328 ◽  
Author(s):  
Ji Ming Bian ◽  
Li Hua Miao ◽  
Shu Kuo Zhao

VO2films were grown on sapphire substrates by pulsed laser deposition (PLD), and the structural and optical properties of as-grown films were investigated by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), photoluminescence (PL), and optical-transmission measurements. The oxygen partial pressure in the growth chamber was found to be the key factor deciding the microstructure and properties of as-deposited VO2films, and its effects and corresponding mechanism were investigated systemically. Results indicated that dense and uniform VO2films with smooth surface were achieved by PLD under optimized oxygen partial pressure. Strong blue emission peaks were observed in room temperature photoluminescence (PL) spectra. Excellent selective optical-transmission of the VO2thin films from 200~3000 nm were also recorded at room temperature.


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