Cu Induced Optical Transitions in MOCVD Grown Cu Doped GaN

2005 ◽  
Vol 892 ◽  
Author(s):  
Jayantha Senawiratne ◽  
Martin Strassburg ◽  
Adam Payne ◽  
Ali Asghar ◽  
William Fenwick ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Structural Properties ◽  
Mass Spectroscopy ◽  
Optical Transitions ◽  
High Crystalline Quality ◽  
Sapphire Substrates ◽  
Secondary Ion

AbstractOptical and structural properties of in situ Cu doped GaN thin films grown on sapphire substrates were optically investigated by means of Raman, photoluminescence (PL), and absorption spectroscopy. Different Cu concentrations in the films were analyzed by secondary ion mass spectroscopy (SIMS) and found to vary from 2×1016cm-3to 5×1017cm-3. Raman studies confirmed high crystalline quality of GaN:Cu with no major structural damages due to Cu incorporation. PL investigation revealed that the origin of the emission around 2.4 eV is most likely due to Cu incorporation. The electrical conductivity of the samples was analyzed by Hall measurements and the found semi-insulating behavior was assigned to the compensation of intrinsic donors by the deep Cu acceptor states.

Structural properties of the epitaxial CuCr0.95Mg0.05O2 thin films on c-plane sapphire substrates by pulsed laser deposition

2011 ◽  
Vol 326 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Se-Yun Kim ◽  
Sang-Yun Sung ◽  
Kwang-Min Jo ◽  
Joon-Hyung Lee ◽  
Jeong-Joo Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Structural Properties ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Sapphire Substrates

Growth of (0001) ZnO Thin Films on Sapphire

1996 ◽  
Vol 449 ◽  
Author(s):  
A. J. Drehman ◽  
P. W. Yip
Keyword(s):  
Surface Roughness ◽  
Buffer Layers ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
Force Microscopy ◽  
Sapphire Substrates ◽  
Atomic Force

ABSTRACTUsing reactive rf sputtering, we have grown (0001) oriented ZnO films in situ on heated c-axis sapphire substrates, that are promising, particularly in terms of surface roughness, as buffer layers for the subsequent epitaxial growth of III-V nitride films. We compare the effects of on-axis and off-axis sputter geometries on the film epitaxy and smoothness. We also examined the effect of substrate temperature on the growth and smoothness and quality of the film. X-ray diffraction was used to verify the hexagonal ZnO phase, its c-axis orientation and, qualitatively, the degree of its epitaxy. Atomic Force Microscopy (AFM) was used to determine the ZnO growth morphology and roughness. Our best films, obtained by off-axis sputter deposition, have a surface roughness of less than 1 nm.

Growth and study of BaZrO3 thin films by pulsed excimer laser ablation

2003 ◽  
Vol 784 ◽  
Author(s):  
V. Rajasekarakumar ◽  
P. Victor ◽  
R. Ranjith ◽  
S. Saha ◽  
S. Rajagopalan ◽  
...  
Keyword(s):  
Thin Films ◽  
Secondary Ion Mass Spectrometry ◽  
Ex Situ ◽  
Silicon Substrates ◽  
Frequency Regime ◽  
Different Temperatures ◽  
The Right ◽  
Limiting Case ◽  
Secondary Ion

ABSTRACTThin films of BaZrO3 (BZ) were grown using a pulsed laser deposition technique on platinum coated silicon substrates. Films showed a polycrystalline perovskite structure upon different annealing procedures of in-situ and ex-situ crystallization. The composition analyses were done using Energy dispersive X-ray analysis (EDAX) and Secondary ion mass spectrometry (SIMS). The SIMS analysis revealed that the ZrO2 formation at the right interface of substrate and the film leads the degradation of the device on the electrical properties in the case of ex-situ crystallized films. But the in-situ films exhibited no interfacial formation. The dielectric properties have been studied for the different temperatures in the frequency regime of 40 Hz to 100kHz. The response of the film to external ac stimuli was studied at different temperatures, and it showed that ac conductivity values in the limiting case are correspond to oxygen vacancy motion. The electrical modulus is fitted to a stretched exponential function and the results clearly indicate the presence of the non-Debye type of dielectric relaxation in these materials.

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