Radiative Recombination Rates in GaN, InN, AlN and their Solid Solutions

1996 ◽  
Vol 423 ◽  
Author(s):  
A. V. Dmitriev ◽  
A. L. Oruzheinikov
Keyword(s):  
Solid Solutions ◽  
Radiative Recombination ◽  
Energy Gap ◽  
Wide Band ◽  
Linear Interpolation ◽  
Recombination Rates ◽  
Wide Band Gap ◽  
Wide Range ◽  
Conductivity Band ◽  
First Time

AbstractThe radiative recombination rates have been calculated for the first time in the wide band gap wurtzite semiconductors GaN, InN and AIN and their solid solutions GaxAl1−xN and InxAl1−xN on the base of existing data on the energy band structure and optical absorption in these materials. We calculated the interband matrix elements for the direct optical transitions between the conductivity band and the valence one using the experimental photon energy dependence of the absorption coefficient near the band edge. In our calculations we assumed that the material parameters of the solid solutions (the interband matrix element, carrier effective masses and so on) could be obtained by a linear interpolation between their values in the alloy components. The temperature dependence of the energy gap was taken in the form proposed by Varshni. The calculations of the radiative recombination rates were performed in the wide range of temperature and alloy compositions.

scholarly journals The Rate of Radiative Recombination in the Nitride Semiconductors and Alloys

1996 ◽  
Vol 1 ◽  
Author(s):  
Alexey V. Dmitriev ◽  
Alexander L. Oruzheinikov
Keyword(s):  
Solid Solutions ◽  
Radiative Recombination ◽  
Energy Gap ◽  
Wide Band ◽  
Linear Interpolation ◽  
Recombination Rates ◽  
Wide Band Gap ◽  
Wide Range ◽  
Conductivity Band ◽  
First Time

The radiative recombination rates have been calculated for the first time in the wide band gap wurtzite semiconductors GaN, InN and AlN and their solid solutions GaxAl1−xN and InxAl1−xN on the base of existing data on the energy band structure and optical absorption in these materials. We calculated the interband matrix elements for the direct optical transitions between the conductivity band and the valence one using the experimental photon energy dependence of the absorption coefficient near the band edge. In our calculations we assumed that the material parameters of the solid solutions (the interband matrix element, carrier effective masses and so on) could be obtained by a linear interpolation between their values in the alloy components. The temperature dependence of the energy gap was taken in the form proposed by Varshni. The calculations of the radiative recombination rates were performed in the wide range of temperature and alloy compositions.

scholarly journals Hybrid ZnO/MoS2 Core/Sheath Heterostructures for Photoelectrochemical Water Splitting

Applied Nano ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 148-161
Author(s):  
Katerina Govatsi ◽  
Aspasia Antonelou ◽  
Labrini Sygellou ◽  
Stylianos G. Neophytides ◽  
Spyros N. Yannopoulos
Keyword(s):  
Visible Light ◽  
Wide Band ◽  
Nanowire Arrays ◽  
Maximum Efficiency ◽  
Light Illumination ◽  
Wide Band Gap ◽  
Long Term Stability ◽  
Visible Light Illumination ◽  
Nanowire Surface ◽  
Wide Range

The rational synthesis of semiconducting materials with enhanced photoelectrocatalytic efficiency under visible light illumination is a long-standing issue. ZnO has been systematically explored in this field, as it offers the feasibility to grow a wide range of nanocrystal morphology; however, its wide band gap precludes visible light absorption. We report on a novel method for the controlled growth of semiconductor heterostructures and, in particular, core/sheath ZnO/MoS2 nanowire arrays and the evaluation of their photoelectrochemical efficiency in oxygen evolution reaction. ZnO nanowire arrays, with a narrow distribution of nanowire diameters, were grown on FTO substrates by chemical bath deposition. Layers of Mo metal at various thicknesses were sputtered on the nanowire surface, and the Mo layers were sulfurized at low temperature, providing in a controlled way few layers of MoS2, in the range from one to three monolayers. The heterostructures were characterized by electron microscopy (SEM, TEM) and spectroscopy (XPS, Raman, PL). The photoelectrochemical properties of the heterostructures were found to depend on the thickness of the pre-deposited Mo film, exhibiting maximum efficiency for moderate values of Mo film thickness. Long-term stability, in relation to similar heterostructures in the literature, has been observed.

Interaction-determined sensitization photodegradation of dye complexes by boron nitride under visible light irradiation: experimental and theoretical studies

2020 ◽  
Vol 44 (22) ◽  
pp. 9238-9247
Author(s):  
Xin Ji ◽  
Yong Guo ◽  
Shugui Hua ◽  
Huiyan Li ◽  
Sunchen Zhang
Keyword(s):  
Boron Nitride ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Wide Band ◽  
Light Irradiation ◽  
Theoretical Studies ◽  
Wide Band Gap ◽  
First Time ◽  
Experimental And Theoretical Studies

In this paper, the sensitization photodegradation of single and mixed dyes by wide band gap boron nitride (BN, 3.94 eV) under visible light irradiation has been investigated for the first time.

scholarly journals β-Ga2O3 Used as a Saturable Absorber to Realize Passively Q-Switched Laser Output

2021 ◽  
Author(s):  
Baizhong Li ◽  
Qiudi Chen ◽  
Peixiong Zhang ◽  
Ruifeng Tian ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Solid State ◽  
Maximum Output Power ◽  
Wide Band ◽  
Output Coupling ◽  
Maximum Output ◽  
Wide Band Gap ◽  
Saturable Absorbers ◽  
Maximum Pulse Energy ◽  
First Time ◽  
State 1

β-Ga2O3 crystal have attracted great attentions in the fields of photonics and photoelectronics because of its ultra wide-band gap and high thermal conductivity. Here, pure β-Ga2O3 crystal was successfully grown by optical floating zone (OFZ) method, and used as saturable absorbers to realize a passively Q-switched all-solid-state 1μm laser for the first time. By placing the as-grown β-Ga2O3 crystal into the resonator of Nd:GYAP solid-state laser, a Q-switched pulses at the center wavelength of 1080.4 nm are generated under a output coupling of 10%. The maximum output power is 191.5 mW while the shortest pulse width is 606.54 ns, and the maximum repetition frequency is 344.06 kHz. The maximum pulse energy and peak power are 0.567 μJ and 0.93 W, respectively. Our experimental results show that β-Ga2O3 crystal has great potential in the development of all-solid-state 1μm pulsed laser.

Theoretical Analysis of the DOS and Band Structural Properties of Ti1-XSnxO2 Solid Solutions

2012 ◽  
Vol 465 ◽  
pp. 33-36
Author(s):  
Zhi Dong Lin ◽  
Wen Long Song ◽  
Ju Cheng Zheng
Keyword(s):  
Band Gap ◽  
Solid Solutions ◽  
Density Functional ◽  
Wide Band ◽  
Low Energy ◽  
Low Density ◽  
First Principle ◽  
Wide Band Gap ◽  
Functional Theory ◽  
First Principle Calculations

The band structure and density of states (DOS) of Ti1-xSnxO2 solid solutions with x=0, 1/8, 1/4, 1/2 and 1 were investigated by means of the first-principle calculations based on density functional theory. The result indicated that band gap and Fermi level of TiO2-SnO2 vary continuously from those of pure TiO2 to those of Sn content increasing. In addition, the DOS moves towards low energy and the bang gap is broadened with growing value of x. The wide band gap and the low density of the states in the conduction band result in the enhancement of photoactivity in Ti1-xSnxO2.

Cubic MgxZn1−xO wide band gap solid solutions synthesized at high pressures

2005 ◽  
Vol 17 (21) ◽  
pp. 3377-3384 ◽  
Author(s):  
A N Baranov ◽  
V L Solozhenko ◽  
C Chateau ◽  
G Bocquillon ◽  
J P Petitet ◽  
...  
Keyword(s):  
Band Gap ◽  
Solid Solutions ◽  
High Pressures ◽  
Wide Band ◽  
Wide Band Gap

THERMAL PROCESSING OF BUNDLED TUNGSTEN OXIDE NANOWIRES

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1541-1547 ◽  
Author(s):  
SHIBIN SUN ◽  
YIMIN ZHAO ◽  
YONGDE XIA ◽  
ZENGDA ZOU ◽  
GUANGHUI MIN ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Wide Band ◽  
Temperature Limit ◽  
Wide Band Gap ◽  
Significant Drop ◽  
Oxide Nanowires ◽  
First Time

Taking the wide band gap one-dimensional (1-D) tungsten oxide nanowires as an example, we here demonstrate systematically the physical characteristics of thermally processed nanowires at temperatures ranging from 400°C to 1000°C, for the first time. Accompanied by a significant drop of specific surface area from 151 m2/g for the as-prepared nanowires to 109 m2/g and 66 m2/g subject to annealing at 400°C and 450°C, dramatically morphology evolution and phase transformation have also been observed. The nanostructured bundles became straighter, larger in diameters and shorter in length, and eventually became irregular particles with size up to 5 µm. The Brunauer-Emmett-Tettler (BET) result suggests that 400°C can be considered as a top temperature limit in nanodevice design where high surface area is important, e.g. in gas sensors. A protocol for thermally processing of these bundled tungsten nanowires has been established.

Synthesis of Various ZnO Nanotree Morphologies through PEG-Assisted Co-Precipitation Method

2015 ◽  
Vol 1112 ◽  
pp. 66-70 ◽  
Author(s):  
Robert Mahendra ◽  
Mariesta Arianti ◽  
Dyah Sawitri ◽  
Doty Dewi Risanti
Keyword(s):  
Wide Band ◽  
Volume Density ◽  
Zinc Nitrate ◽  
Single Step ◽  
Precipitation Method ◽  
Transparent Electronics ◽  
Wide Band Gap ◽  
Wide Range ◽  
Co Precipitation ◽  
Branched Nanostructures

ZnO, with direct wide band gap of 3.37 eV and high excitonic binding energy of 60 meV has been attracting much attention due to its wide range of applications, for transparent electronics, solar cells, and other optoelectronics device. We present a simple, single step process to produce ZnO nanotrees using co-precipitation method. As a precursor, zinc nitrate dehydrate was stabilized by hexamethylene tetraamine (HMTA) and 3-9 mM polyethylene glycol (PEG) was added at 180°C for 3-6 hours followed by residual polymer removal. Scanning Electron Microscopy revealed the typical rod-like branched nanostructures were achieved. For longer annealing time the PEG-assisted growth process indeed exhibited a distinctive c-direction inhibition responsible for the lateral growth and subsequent branching of ZnO, in which the branch growth in sample with PEG amount of 0.05 g is the slowest. Some amounts of PEG up to 0.03 g are sensitive to affect several parameters, such as, lattice stress, unit cell volume, density of film and dislocation density.

scholarly journals Copper-doped quasi-one-dimensional ZnO for effective photooxidation of As (III) to As (V) in visible light

2020 ◽  
Author(s):  
Olga I. Gyrdasova ◽  
Vladimir N. Krasil’nikov ◽  
Natalya S. Sycheva
Keyword(s):  
Solid Solutions ◽  
Electron Acceptor ◽  
Particle Morphology ◽  
Wide Band ◽  
Wide Band Gap ◽  
One Dimensional ◽  
Precursor Synthesis ◽  
One Step ◽  
Wide Band Gap Semiconductors ◽  
Doped Zno

By temolysis of the Zn1−  Cu (HCOO)(OCH2CH2O)1/2 complexes in one step Zn1−  Cu O solid solutions were obtained. Сopper in these materials is a regulator of the photoactivity and morphology of aggregates. According to TEM, XPS, optical spectroscopy, and voltammetry, all samples studied contain monovalent copper. It was shown that the maximum photoactivity in the reactions of photooxidation of As in UV and blue light has Zn1− Cu O (0<x<0.1) solid solutions with tubular particle morphology. With an increase in concentration up to 10 at.%, сopper manifests itself as an electron acceptor, which reduces the efficiency of the catalyst in both light ranges. Keywords: photocatalyst, Cu-doped ZnO, heterostructures, wide-band-gap semiconductors, precursor synthesis

Sign in / Sign up

Export Citation Format

Share Document