Room-temperature spin glass and near band edge properties of highly disorder (FeCo)0.03Zn0.97O and (FeCoNi)0.03Zn0.97O nanorods

2010 ◽  
Vol 107 (4) ◽  
pp. 043902 ◽  
Author(s):  
Javed Iqbal ◽  
Xiaofang Liu ◽  
Naeem Ahmad ◽  
Takashi Harumoto ◽  
Dapeng Yu ◽  
...  
Keyword(s):  
Spin Glass ◽  
Room Temperature ◽  
Band Edge ◽  
Near Band Edge

Near band edge photoacoustic spectra od GaAs below room temperature

1990 ◽  
Vol 121 (1) ◽  
pp. K125-K127 ◽  
Author(s):  
T. Ikari ◽  
H. Yokoyama ◽  
K. Maeda ◽  
K. Futagami
Keyword(s):  
Room Temperature ◽  
Band Edge ◽  
Near Band Edge ◽  
Photoacoustic Spectra

Properties Of Epitaxial Cdte On Si(lll) With a (Ca,Ba)F2 Buffer Layer

1987 ◽  
Vol 91 ◽  
Author(s):  
H. Zogg ◽  
S. Blunier
Keyword(s):  
Thermal Expansion ◽  
Buffer Layer ◽  
Room Temperature ◽  
Band Edge ◽  
Structural Quality ◽  
Near Band Edge ◽  
Thermal Expansion Mismatch ◽  
X Ray ◽  
Device Applications ◽  
Near Band Edge Peak

ABSTRACTEpitaxial CdTe has been grown onto Si(lll) wafers by MBE with the aid of a composition graded (Ca,Ba)F2 buffer layer to surmount the large misfit of 19%. Untwinned CdTe layers with smooth surfaces, narrow X-ray lines and strong photoluminescence with a narrow near band edge peak were obtained. The results indicate a comparable structural quality to well known CdTe layers on sapphire, InSb or GaAs used as buffers to grow (Hg, Cd)Te for IR-device applications. In addition, the CdTe layers are near strain free despite a large thermal expansion mismatch. This is most probably due to dislocations which are able to move along the fluoride/Si interface even after growth and down to near room temperature.

Unusual near-band-edge photoluminescence at room temperature in heavily-doped ZnO:Al thin films prepared by pulsed laser deposition

2013 ◽  
Vol 140 (2-3) ◽  
pp. 610-615 ◽  
Author(s):  
Bhaskar Chandra Mohanty ◽  
Deuk Ho Yeon ◽  
Sachindra Nath Das ◽  
Ji Hye Kwak ◽  
Kyung Hoon Yoon ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Band Edge ◽  
Near Band Edge ◽  
Heavily Doped

The compositional and optical characterizations of InGaAsN alloy semiconductor grown by MOVPE

2002 ◽  
Vol 744 ◽  
Author(s):  
Sakuntam Sanorpim ◽  
Fumihiro Nakajima ◽  
Ryuji Katayama ◽  
Kentaro Onabe ◽  
Yashihiro Shiraki
Keyword(s):  
Room Temperature ◽  
Excitation Power ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Optical Investigation ◽  
Edge Emission ◽  
Alloy Films ◽  
Pl Spectra

ABSTRACTWe report on the compositional and optical investigation of InGaAs(N) alloy films grown on GaAs (001) substrates by low-pressure (60 Torr) metalorganic vapor phase epitaxy (MOVPE). The alloy films with the room-temperature photoreflactance (PR) signal (Eo transition) wavelength range of 0.98–1.36 m have been grown. The variation in PL characteristics of the InGaAs(N) alloy films has been investigated as a function of alloy composition, excitation power and temperature. At low temperatures (T<100K), the PL spectra with several sub-peaks include localization emission as well as near-band-edge emission. On the other hand, the room-temperature PL properties for InxGa1-xAs1-yNy (x = 10.5% and 17.0% and y < 2%) are excellent with a single near-band-edge emission peak corresponding to their own Eo transition. The evolution of PL spectra with excitation power and temperature led to an insight into the nature of the near-band-edge states. The temperature dependence of integrated PL intensity indicates the presence of a large density of non-radiative recombination centers, showing a behavior characterized by two activation energies. Our results suggest that the origin of localization in InGaAsN alloy films is the alloy inhomogeneities of both In and N, which may results in the characteristic carrier dynamics.

Si- and SiGe-Based LEDs

2008 ◽  
Vol 590 ◽  
pp. 79-100 ◽  
Author(s):  
N.A. Sobolev
Keyword(s):  
Room Temperature ◽  
Radiation Power ◽  
Record Values ◽  
Band Edge ◽  
Near Band Edge ◽  
Interband Transitions ◽  
Emission Power ◽  
Light Emitters ◽  
Light Emitting ◽  
Temperature Ranges

Single crystal Si, Si0.948Ge0.052 and Si0.66Ge0.34 diodes as well as Ge transistor structures with high electroluminescence (EL) intensities in the region of interband transitions at room temperature were fabricated by different techniques and their luminescence properties were studied. By varying the Ge content in the solid solution, one can control the wavelength at the emission maximum in the range of 1.1 - 1.8 μm. The integrated EL intensity varies by a factor of less than two in the temperature ranges of 80 - 500 and 80 - 300 K for Si and SiGe LEDs, respectively. Si LEDs can effectively operate, at least, up to ~200°C. The data analysis shows that recombination involving excitons is the dominant mechanism of near-band-edge radiative recombination in all the light-emitting structures at room temperature. Some of the structures have record values of EL intensity and/or quantum efficiency, so they can be used as effective light emitters in Si optoelectronics. In particular, Si LEDs were designed with a small p-n junction area of 8x10-3 mm2 and a radiation power of 0.3 mW. The record total emission power of 46 mW was achieved in solar cell LEDs with an emitting surface area of 3 сm2. The internal quantum efficiencies of 0.5% and 0.3% were recorded in Si0.948Ge0.052 and Si0.66Ge0.34 LEDs at the wavelengths of 1.15 and 1.3 μm, respectively. Room temperature near-band-edge EL was first observed in Ge structures.

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