Tri-allylthiourea mercury chloride(ATMC),an organometallic complex,is a new nonlinear optical material with high second harmonic generation(SHG)effect.The SHG effect of ATMC is three times as large as that of urea cry...Tri-allylthiourea mercury chloride(ATMC),an organometallic complex,is a new nonlinear optical material with high second harmonic generation(SHG)effect.The SHG effect of ATMC is three times as large as that of urea crystal.Transparent single crystal of 15×15×10mm^(3) has been grown.Comprehensive studies of crystal growth,structure,and general properties have been carried out.The results show that organometallic complexes are promising nonlinear optical materials for wide applications.展开更多
Under electron beam irradiation,the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed.The homogenous transition mainly occurs at the thin edge and on th...Under electron beam irradiation,the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed.The homogenous transition mainly occurs at the thin edge and on the surface of specimen where the energy obtained from electron beam irradiation is high enough to cause the amorphous crystallizing into 2H-SiC.展开更多
SiC substrates grown by the sublimation method still have high densities of structural defects such as dislocations,micropipes,low-angle grain boundaries,macrodefects and polytypes.Wet etching was effectively used to ...SiC substrates grown by the sublimation method still have high densities of structural defects such as dislocations,micropipes,low-angle grain boundaries,macrodefects and polytypes.Wet etching was effectively used to study the defects of SiC.Etch pit shapes of defects and their origins were discussed.Most of the defects originate in the initial growth stage.Thus to optimize the early growth conditions especially the temperature distribution is a crucial problem.展开更多
Lattice matched GaInP/GaAs heterostructures were grown by atmospheric pressuremetal organic vapor phase epitaxy(AP-MOVPE).Compositional intermixing of As/P and Ga/In near the heterointerfaces was studied by photolumin...Lattice matched GaInP/GaAs heterostructures were grown by atmospheric pressuremetal organic vapor phase epitaxy(AP-MOVPE).Compositional intermixing of As/P and Ga/In near the heterointerfaces was studied by photoluminescence(PL)spectroscopy.Indium segregation,memory effect of In into GaAs and the carry-over of As in the GaInP layer during the growth process were considered as three major factors giving rise to the anomalous emissions in the PL spectra.Both thermal annealing and zinc doping strongly enhanced the compositional interdiffusion near the heterointerfaces.展开更多
In this paper,by comparing the three possible combinations of the basic structure unit TiO_(6) octahedra,a simple model is proposed to explain the cause of the formation of the bicrystal structure in KTiOPO_(4)(KTP)cr...In this paper,by comparing the three possible combinations of the basic structure unit TiO_(6) octahedra,a simple model is proposed to explain the cause of the formation of the bicrystal structure in KTiOPO_(4)(KTP)crystals.The theoretical morphology of KTP crystal is studied and the rate of the appearance possibilities of different faces are obtained.The relationships between bicrystal structure and crystal properties are discussed.展开更多
We have grown two structures of AlAs/GaAs/AlAs double barrier resonant tunneling diodes by metal-organic chemical vapor deposition.The resonances to the first excited states were obtained,the measured peak-to-valley c...We have grown two structures of AlAs/GaAs/AlAs double barrier resonant tunneling diodes by metal-organic chemical vapor deposition.The resonances to the first excited states were obtained,the measured peak-to-valley current ratio is 1.3 at 77 K,room temperature peak current is 8kA/cm^(2),the resonance voltages are in agreement with the theoretical approach by transfer-matrix method.展开更多
A prospective new organic material:3-methoxy-4-hydroxy-benzaldehyde(MHBA)with powder second harmonic generation efficiency 30 times as large as that of urea and the cutoff wavelength of 370nm is reported.MHBA belongs ...A prospective new organic material:3-methoxy-4-hydroxy-benzaldehyde(MHBA)with powder second harmonic generation efficiency 30 times as large as that of urea and the cutoff wavelength of 370nm is reported.MHBA belongs to monoclinic system space group P2_(1),and the unit cell parameters are:a=14.057Å,b=7.875Å,c=15.037Åandβ=115.45°,the general physicalchemical properties are also presented.展开更多
Tri-allyIthiourea cadmium chloride(ATCC),an organometallic complex,is a new nonlinear optical material with high second harmonic generation(SHG)effect.Transparani single crystal of 30×30×25mm has been grown....Tri-allyIthiourea cadmium chloride(ATCC),an organometallic complex,is a new nonlinear optical material with high second harmonic generation(SHG)effect.Transparani single crystal of 30×30×25mm has been grown.Com-prehensive studies of crystal growth,structure and general properties have been carried out.The results show that organometallic complexes are promising nonlinear optical materials for wide applications.展开更多
Using dye laser as pumping light source,we have first realized on NYAB crystal the laser self-frequency doubling run from 1.06μm to 0.53μm.The threshold energy is less than 4mJ;conversion efficiency is 6.2%,and the ...Using dye laser as pumping light source,we have first realized on NYAB crystal the laser self-frequency doubling run from 1.06μm to 0.53μm.The threshold energy is less than 4mJ;conversion efficiency is 6.2%,and the self-frequency-doubling green light output energy is 2.5mJ.展开更多
基金Projects supported by the National Science Fundation of China(918700100).
文摘Tri-allylthiourea mercury chloride(ATMC),an organometallic complex,is a new nonlinear optical material with high second harmonic generation(SHG)effect.The SHG effect of ATMC is three times as large as that of urea crystal.Transparent single crystal of 15×15×10mm^(3) has been grown.Comprehensive studies of crystal growth,structure,and general properties have been carried out.The results show that organometallic complexes are promising nonlinear optical materials for wide applications.
基金Project supproted by the National Natural Science Foundation of China(60025409 and 50472068)National"863"High Technology Plan(2001AA311080)Program for New Century Excellent Talents in Shangdong University
文摘Under electron beam irradiation,the in-situ formation of 2H-SiC dentritic nanocrystals from amorphous silicon carbide at room temperature was observed.The homogenous transition mainly occurs at the thin edge and on the surface of specimen where the energy obtained from electron beam irradiation is high enough to cause the amorphous crystallizing into 2H-SiC.
基金Project supported by the National Natural Science Foundation of China(60025409 and 50472068)National"863"High Technology Plan(2001AA311080)
文摘SiC substrates grown by the sublimation method still have high densities of structural defects such as dislocations,micropipes,low-angle grain boundaries,macrodefects and polytypes.Wet etching was effectively used to study the defects of SiC.Etch pit shapes of defects and their origins were discussed.Most of the defects originate in the initial growth stage.Thus to optimize the early growth conditions especially the temperature distribution is a crucial problem.
文摘Lattice matched GaInP/GaAs heterostructures were grown by atmospheric pressuremetal organic vapor phase epitaxy(AP-MOVPE).Compositional intermixing of As/P and Ga/In near the heterointerfaces was studied by photoluminescence(PL)spectroscopy.Indium segregation,memory effect of In into GaAs and the carry-over of As in the GaInP layer during the growth process were considered as three major factors giving rise to the anomalous emissions in the PL spectra.Both thermal annealing and zinc doping strongly enhanced the compositional interdiffusion near the heterointerfaces.
基金Supported by a grant for Key Research Projection Climbing Program from the State Science and Technology Commission of China。
文摘In this paper,by comparing the three possible combinations of the basic structure unit TiO_(6) octahedra,a simple model is proposed to explain the cause of the formation of the bicrystal structure in KTiOPO_(4)(KTP)crystals.The theoretical morphology of KTP crystal is studied and the rate of the appearance possibilities of different faces are obtained.The relationships between bicrystal structure and crystal properties are discussed.
基金Supported by the National Natural Science Foundation of China.
文摘We have grown two structures of AlAs/GaAs/AlAs double barrier resonant tunneling diodes by metal-organic chemical vapor deposition.The resonances to the first excited states were obtained,the measured peak-to-valley current ratio is 1.3 at 77 K,room temperature peak current is 8kA/cm^(2),the resonance voltages are in agreement with the theoretical approach by transfer-matrix method.
基金Supported by the National Natural Science Foundation(918700100).
文摘A prospective new organic material:3-methoxy-4-hydroxy-benzaldehyde(MHBA)with powder second harmonic generation efficiency 30 times as large as that of urea and the cutoff wavelength of 370nm is reported.MHBA belongs to monoclinic system space group P2_(1),and the unit cell parameters are:a=14.057Å,b=7.875Å,c=15.037Åandβ=115.45°,the general physicalchemical properties are also presented.
文摘Tri-allyIthiourea cadmium chloride(ATCC),an organometallic complex,is a new nonlinear optical material with high second harmonic generation(SHG)effect.Transparani single crystal of 30×30×25mm has been grown.Com-prehensive studies of crystal growth,structure and general properties have been carried out.The results show that organometallic complexes are promising nonlinear optical materials for wide applications.
文摘Using dye laser as pumping light source,we have first realized on NYAB crystal the laser self-frequency doubling run from 1.06μm to 0.53μm.The threshold energy is less than 4mJ;conversion efficiency is 6.2%,and the self-frequency-doubling green light output energy is 2.5mJ.
