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Electrical and deep levels characteristics of ZnO/Si heterostructure by MOCVD deposition

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Chinese Physics B 2008年第6期17卷 2292-2296页

作者：刘磁辉刘秉策付竹西 Department of Physics University of Science and Technology of China Department of Electron Science and Technology University of Science and Technology of China

ZnO films have been prepared on p-type Si substrates by metal-organic chemical vapour deposition （MOCVD） at different total gas flow rates. The current versus voltage and temperature （I - V - T） characteristics, the deep-level transient spectroscopy （DLTS） and the photoluminescence （pl） spectra of the samples were measured. DLTS shows two deep-level centres of E1 （Ec-0.13±0.02eV） and E2 （Ec-0.43±0.05eV） in sample 1202a, which has a ZnO/p-Si heterostructure. A deep level at Ec-0.13±0.01 eV was also obtained from the I -T characteristics. It was considered to be the same as E1 obtained from DLTS measurement. The emission related to this deep level center was detected by pl spectra. In addition, the energy location and the relative trap density of E1 was varied when the total gas flow rate was changed.

关键词： MOCVD ZnO/Si heterostructure pl spectra deep-level emission

Annealing effects on the photoluminescence of Pb-ion irradiated He-doped sapphire

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Science China(Physics,Mechanics & Astronomy) 2012年第10期55卷 1803-1807页

作者： SONG Yin ZHANG ChongHong HE DeYan ZHANG LiQing GOU Jie YANG YiTao LI JianJian School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

In the present work, the photoluminescence （pl） character of single crystal sapphire （A1203） samples with and without im- plantation by 110 keV He and/or irradiation by 230-MeV Pb ions, as well as subsequently annealing at 600, 900 and 1100 K （TA） was studied. The modification of the structure and optical properties induced by ion irradiation were analyzed by using pl and FTIR spectra. The pl measurements showed that luminescence peaks located at 390, 413,450, and 564 nm appeared in irradiated samples. The luminescence peaks appeared at 360, 380, and 516 nm after annealing. Infrared spectra showed a broad- ening of the absorption band between 460 cm^-1 and 510 cm^-1, which indicated the formation of strongly damaged regions in the Al2O3 samples. The position shift of the absorption band in 1000-1300 cm^-1 tended towards to a higher wavelength.

关键词： ion irradiation Al2O3 pl spectra

Photoluminescence and defect evolution of nano-ZnO thin films at low temperature annealing

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Science China(Technological Sciences) 2013年第1期56卷 25-31页

作者： YANG AiLing YANG Yun ZHANG ZhenZhen BAO XiChang YANG RenQiang LI ShunPin SUN Liang Department of Physics Ocean University of China Qingdao Institute of Bioenergy & Bioprocess Technology Chinese Academy of Sciences

Nano-ZnO thin films composed of nanoparticles with sizes of 10-16 nm on silicon substrates at low temperature were prepared by sol-gel *** placing the nano-ZnO thin films at room temperature or annealing at 100°C in air for 10 h intermittently,within a total 70 h annealing time,the evolution of pl spectra of the nano-ZnO thin films were studied in *** the annealing time increases,the pl peaks shift from violet to blue and green *** pl peaks at violet and blue bands decrease with the annealing time,but the pl peaks at green band are *** pl spectra are related to the defects in the nano-ZnO thin *** pl peaks positioned at 430 nm are mainly related to defects of zinc interstatials(Zni),oxygen vacancies and(Vo);the ones at 420 nm to oxygen interstitials(Oi),Zinc vacancies(Vzn),Zni ;and the ones at 468 nm to Vzn,Zni,and charged oxygen interstatials(Vo+).The green luminescence is related to Oi,Vo and *** evolutions of pl spectra and the defects are also related to the concentrations of Zn in the thin films,the thicknesses of the films and the annealing *** the films with 0.5 M and 1.0 M Zn concentrations,after 20 h and 30 h annealing in air at 100°C,respectively,either placing them in air at room temperature or continuing anneal in air at 100°C,the pl spectra are *** the low temperature annealing,Zni decreases with the annealing time,and Oi *** Oi favors to keep the nano-ZnO thin films *** result is important to nano-ZnO thin films as electron transport layers in inverted or tandem organic solar cells.

关键词： nano-ZnO thin films low temperature annealing pl spectra defects

Analysis of the anisotropy in an m-plane GaN film via HVPE on a γ-LiAlO_2 substrate

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Journal of Semiconductors 2009年第9期30卷 13-15页

作者：田密修向前张荣华雪梅刘战辉韩平谢自力郑有炓 Key Laboratory of Advanced Photonic and Electronic Materials Department of PhysicsNanjing University

A 0.09 mm m-plane GaN film is deposited via hydride vapor phase epitaxy （HVPE） on a γ-LiAlO2 substrate. To research the anisotropy between directions with different angles with the c-axis in the m plane, photoluminescence （pl） measurements were carried out. The results show that the electronic transition was influenced by the electric field along the c-axis, which results in an obvious anisotropy, but the influence was weakened by the hexagonal symmetry along the c-axis.

关键词： γ-LiAlO2 GaN HVPE anisotropy pl spectra

plE spectra analysis of the sub-structure in the absorption spectra of CdSeS quantum dots

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Chinese Physics B 2006年第5期15卷 1067-1070页

作者：刘炳灿潘学琴田强吴正龙 The Department of Fundamental Courses The Academy of Armored Force Engineering Beijing 100072 China Department of Physics Beijing Normal University Beijing 100875 China Analytical and Testing Center Beijing Normal University Beijing 100875 China

The semiconductor CdSeS quantum dots （QDs） embedded in glass are analysed by means of absorption spectra, photoluminescence （pl） spectra and photoluminescence excitation （plE） spectra. The peaks of absorption spectra shift to lower energies with the size of QD increasing, which obviously shows a quantum-size effect. Using the plE spectra, the physical origin of the lowest absorption peak is analysed. In plE spectra, the lowest absorption peak can be deconvoluted into two peaks that stem from the transitions of 1S3/2-1Se and 2S3/2-1Se respectively. The measured energy difference between the two peaks is found to decrease with the size of QD increasing, which agrees well with the theoretical calculation for the two transitions. The luminescence peak of defect states is also analysed by plE spectra. Two transitions are present in the plE, which indicates that the transitions of 1S3/2 1Se and 2S3/2 1Se are responsible for the defect states luminescence.

关键词： CdSeS pl spectra plE spectra defect state

Self-assembled germanium nano-structures by laser-assisted oxidation

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Chinese Physics B 2006年第2期15卷 389-393页

作者：黄伟其刘杨荣 Department of Physics Guizhou University Guiyang 550026 China Institute of Geochemistry Chinese Academy of Sciences Guiyang 550003 China Department of Physics Guizhou Educational College Guiyang 550003 China Optoelectronics Physics Lab Gulzhou University Guiyang 550026 China

The investigation on the oxidation behaviour of Si1-xGex alloys （x=0.05, 0.15, and 0.25） is carried out. It is found for the first time that on the oxide film a germanium nano-cap with a thickness of 1.8-2.8nm and a few Ge nanoparticles with diameters ranging from 5.5 nm to 10 nm are formed by the *** laser-assisted dry oxidation of Si1-xGex substrate. A new scanning method on the decline cross-section of the multiple-layer sample is adopted to measure the layer thickness and the composition. Some new peaks in photoluminescence （pl） spectra are discovered, which could be related to the nano-cap and the nano-particles of germanium. A suitable model and several new calculating formulae with the unrestricted Hartree-Fock-Roothaan （UHFR） method and quantum confinement analysis are proposed to interpret the pl spectra and the nano-structure mechanism in the oxide.

关键词： low-temperature oxidation laser-assisted nano-structure pl spectra