Table of Contents
Is ZnO direct band gap?
ZnO is a very promising material for semiconductor device applications [1–5]. It has a direct and wide band gap (figure 1) in the near-UV spectral region [6–10], and a large free-exciton binding energy [6–9] so that excitonic emission processes can persist at or even above room temperature [11, 12].
What is the band gap of zinc oxide?
3.37 eV
Background. Zinc oxide is one of the most important metal oxides due to its unique physical characteristics of wide and direct band gap (~3.37 eV) with a large exciton binding energy (60 meV).
How do you calculate the band gap of a nanoparticle?
By plotting the graph between (ahv)^(1/2) versus photon energy (hv) where, a (alpha) is the absorbance calculated from UV . (hv) can be calculated form wavelength using: (hv = 1240/wavelength);Extrapolating the straight line portion of the curves to zero absorption coefficient value gives the energy band gap value.
What is the electron mobility of ZnO?
presented the growth of a ZnO thin film on c-plane sapphire with a relatively high electron mobility of 169 cm2/Vs and a low carrier concentration of 2 × 1016 cm−3 using plasma-assisted MBE by optimizing the thickness of a MgO buffer layer [12].
What is the band gap of copper oxide?
1.2 eV
Copper oxide (CuO) is a semiconductor with direct wide band gap 1.2 eV, with many useful properties (electrical, catalytic, optical…). A wide range of applications makes it the most studied in the last decade materials, especially when it is developed in the form of nanostructures.
What is band gap in nanoparticles?
The band gap is the region forbidden for the electrons. The larger the forbidden region, the greater the restriction on the movement of electrons. Hence nanoparticles exhibit lower electrical conductivity. There is also a shift the absorption spectrum towards low wavelength blue region or UV region.
Why does ZnO behave as a semiconductor?
ZnO with a wurtzite structure is naturally an n-type semiconductor because of a deviation from stoichiometry due to the presence of intrinsic defects such as O vacancies O(v) and Zn interstitials Zn(i) [1]. Undoped ZnO shows intrinsic n-type conductivity with very high electron densities of about 10^21 cm^−3.
Is ZnO conductive?
Zinc oxide (ZnO) belongs to the class of transparent conducting oxides which can be used as transparent electrodes in electronic devices or heated windows.
Why zinc oxide is semiconductor?
What is intrinsic ZnO?
An intrinsic ZnO film has n-type conductivity but its resistivity is relatively higher than that of ITO because of low carrier concentration. A common method to enhance the conductivity of ZnO is to dope impurities [6] . For example, doping with group 13 elements (B, Al, Ga, In, etc.)
What is the band gap energy of ZnO?
UV–Vis diffuse reflectance spectra showed that optical band gap energy of ZnO has narrowed from 3.11 to 3.08 eV and 3.03 eV when doped with 1% Mg and 5% Mg, respectively. Powder X-ray diffraction and X-ray photoelectron spectroscopy studies confirmed the purity and crystalline nature of the synthesized materials.
What is the electronic structure of ZnO on mg doping?
electronic structure of ZnO on Mg doping. In the doped duction band along with 4 s orbital of Zn. The 3 s orbital of resulting in the widening of the band gap. with the previous reports [ 32, 33 ]. 4. Conclusions method.
What is the band gap between CD and MG nanostructures?
The band gap varied from 3.04 eV in Cd-doped (9.1 at. % of Cd) nanostructure to 3.99 eV in Mg-doped (16.8 at. % of Mg) nanostructure.
Why is doping efficiency of CD lower than that of MG?
The lower doping efficiency of Cd than that of Mg has been explained in terms of binding energy. The band gap varied from 3.04 eV in Cd-doped (9.1 at. % of Cd) nanostructure to 3.99 eV in Mg-doped (16.8 at. % of Mg) nanostructure.