ZnO/CdO composite films with different CdO contents are obtained by pulse laser deposition technique. The structural, optical and electrical properties of the composite [liras are investigated by x-ray diffraction, ph...ZnO/CdO composite films with different CdO contents are obtained by pulse laser deposition technique. The structural, optical and electrical properties of the composite [liras are investigated by x-ray diffraction, photolu- minescence and electrical resistivity measurements, respectively. The results show that the UV emission is at a constant peak position in the photoluminescence spectra. Meanwhile, their electrical resistivity decreases to very low level approaching to the value of the CdO film, which can be explained by the Matthiessen composite rule for resistivity. The peculiarity of low resistivity and high transnlittance in the visible region enables these Rims suitable for optoelectronic device fabrication.展开更多
The electronic structures and optical properties of Y-doped ZnO are calculated using first-principles calculations.It is found that the replacement of Zn by the rare-earth element Y presents a shallow donor,and the Fe...The electronic structures and optical properties of Y-doped ZnO are calculated using first-principles calculations.It is found that the replacement of Zn by the rare-earth element Y presents a shallow donor,and the Fermi level moves into the conduction band(CB).The high dispersion and s-type character of CB is expected to result in an increase in conductivity.Moreover,the absorption spectrum of the Y-doped ZnO system exhibits a slight blue shift with an increase of Y concentration,and a higher transparency in visible light is expected.Therefore,the Y-doping in ZnO would enhance the mobility and hence increase the electrical conductivity without sacrificing the optical transparency,which is essential for the improvement of ZnO's behavior and its performance in extension applications.展开更多
Optical and electronic properties of Zn_(1−x)Mg_(x)O ternary alloys of wurtzite structure are calculated by using first-principles based on the framework of generalized gradient approximation to density functional the...Optical and electronic properties of Zn_(1−x)Mg_(x)O ternary alloys of wurtzite structure are calculated by using first-principles based on the framework of generalized gradient approximation to density functional theory with the introduction of the on-site Coulomb interaction.The use of the𝑈parameter on Zn-3d𝑑and O-2p𝑝orbits is obviously crucial,which can improve the GGA to predict the electronic properties and bandgap of the Zn_(1−x)Mg_(x)O(0≤𝑥≤0.25)system reasonably.It is further demonstrated that the bandgap widens with an increasing Mg concentration from 3.217 eV of ZnO to 3.877 eV of Zn0.75Mg0.25O.Therefore,the theoretical results show that Zn_(1−x)Mg_(x)O ternary alloys are potential candidates for optoelectronic materials,especially for UV photon emitters and detectors.展开更多
基金Supported by the National Nature Science Foundation under Grant No 50871046, the National Basic Research Program of China under Grant No 2010CB631001, and the Program for Changjiang Scholars and Innovative Research Team in University.
文摘ZnO/CdO composite films with different CdO contents are obtained by pulse laser deposition technique. The structural, optical and electrical properties of the composite [liras are investigated by x-ray diffraction, photolu- minescence and electrical resistivity measurements, respectively. The results show that the UV emission is at a constant peak position in the photoluminescence spectra. Meanwhile, their electrical resistivity decreases to very low level approaching to the value of the CdO film, which can be explained by the Matthiessen composite rule for resistivity. The peculiarity of low resistivity and high transnlittance in the visible region enables these Rims suitable for optoelectronic device fabrication.
基金Supported by the National Basic Research Program of China(No 2010CB631001)the National Natural Science Foundation of China(No 50871046)+1 种基金the Programs of Science and Technology Department of Heilongjiang Province(No QC2011C026)the Program for Changjiang Scholars and Innovative Research Team in University.
文摘The electronic structures and optical properties of Y-doped ZnO are calculated using first-principles calculations.It is found that the replacement of Zn by the rare-earth element Y presents a shallow donor,and the Fermi level moves into the conduction band(CB).The high dispersion and s-type character of CB is expected to result in an increase in conductivity.Moreover,the absorption spectrum of the Y-doped ZnO system exhibits a slight blue shift with an increase of Y concentration,and a higher transparency in visible light is expected.Therefore,the Y-doping in ZnO would enhance the mobility and hence increase the electrical conductivity without sacrificing the optical transparency,which is essential for the improvement of ZnO's behavior and its performance in extension applications.
基金by the National Natural Science Foundation of China under Grant No 50871046the National Basic Research Program of China(No 2010CB631001)the Program for Changjiang Scholars and Innovative Research Team in University.
文摘Optical and electronic properties of Zn_(1−x)Mg_(x)O ternary alloys of wurtzite structure are calculated by using first-principles based on the framework of generalized gradient approximation to density functional theory with the introduction of the on-site Coulomb interaction.The use of the𝑈parameter on Zn-3d𝑑and O-2p𝑝orbits is obviously crucial,which can improve the GGA to predict the electronic properties and bandgap of the Zn_(1−x)Mg_(x)O(0≤𝑥≤0.25)system reasonably.It is further demonstrated that the bandgap widens with an increasing Mg concentration from 3.217 eV of ZnO to 3.877 eV of Zn0.75Mg0.25O.Therefore,the theoretical results show that Zn_(1−x)Mg_(x)O ternary alloys are potential candidates for optoelectronic materials,especially for UV photon emitters and detectors.
