以锑化铯(Cs_(3)Sb)为代表的碱金属型半导体光阴极具有高量子效率、低电子发射度、光谱响应快等特点,可作为理想的新型电子发射源.然而Cs_(3)Sb中碱金属敏感于含氧气体,从而导致其结构不稳定,工作寿命低,影响电子发射效率.利用超薄层状...以锑化铯(Cs_(3)Sb)为代表的碱金属型半导体光阴极具有高量子效率、低电子发射度、光谱响应快等特点,可作为理想的新型电子发射源.然而Cs_(3)Sb中碱金属敏感于含氧气体,从而导致其结构不稳定,工作寿命低,影响电子发射效率.利用超薄层状的二维材料进行涂层保护Cs_(3)Sb基底,有望构建新型高性能光阴极材料,但目前仍然缺乏适合的二维材料,能够在保护基底同时维持低功函数(W)和高量子效率.近年来二维过渡金属碳/氮化物(MXene)材料逐渐成为研究热点,其灵活引入的悬挂键可以很好地调控MXene材料的结构和电子特性.本文系统构建了一系列M_(2)CT_(2)-Cs_(3)Sb异质结,基于第一性原理计算分析了过渡金属元素(M)、原子配比(M/C)、堆垛构型及悬挂键(T)等对其W的影响.研究表明,不同悬挂键类型对构建异质结的W影响显著,相对于其他悬挂键(—F/—O/—Cl/—S/—NH),带有—OH/—OCH_(3)悬挂键构成的M_(2)CT_(2)-Cs_(3)Sb异质结具有相对较低的W.利用差分电荷密度和能级矫正分析解释了异质结W的变化原因,即异质结界面电荷重新分布导致界面偶极方向不同,造成电子逸出的势垒不同.经过筛选后发现,M_(2)C(OH)_(2)(M=V,Ti,Cr)和M_(2)C(OCH_(3))_(2)(M=Ti,Cr,Nb)结构可以看作理想的涂层材料,尤其是V_(2)C(OH)_(2)-Cs_(3)Sb(W=1.602 e V)和Ti_(2)C(OCH_(3))_(2)-Cs_(3)Sb(W=1.877 e V).本研究不仅有助于深入理解MXene-Cs_(3)Sb异质结电子结构和光学性质,同时也为高性能光阴极材料的计算筛选提供参考依据.展开更多
In this paper,nanosecond pulsed laser is introduced to selectively ablate away indium tin oxide film and metal film without destroying the underlying layers for fabricating organic light-emitting diodes.By varying den...In this paper,nanosecond pulsed laser is introduced to selectively ablate away indium tin oxide film and metal film without destroying the underlying layers for fabricating organic light-emitting diodes.By varying density of energy,pulse number and width of the laser,the influence on morphology of the laser trenches of indium tin oxide and metal films are investigated.It is presented that uniform ablation trench can be obtained with 16 laser pulses at 0.15 J/cm^2 for aluminum film and 10 laser pulses at 0.65 J/cm^2 for indium tin oxide film.It is found that the characteristics of the organic light-emitting diodes prepared with laser ablation are almost the same as those of that prepared with conventional patterning method.展开更多
X-ray emission from metal cathodes in glow discharge （current is up to 300 mA, voltage is 1,500-4,300 V） experiments in the spectral range from 700 eV to 6 keV has been observed. The effect has been seen with a vari...X-ray emission from metal cathodes in glow discharge （current is up to 300 mA, voltage is 1,500-4,300 V） experiments in the spectral range from 700 eV to 6 keV has been observed. The effect has been seen with a variety of different metal cathodes （including AI, Sc, Ti, V, Ni, Nb, Zr, Mo, Pd, Ta, W, and Pt）, as well as with different gasses （including D2, H2, Kr, Ar, and Xe） at low pressure （3-10 Torr）. We present results from a variety of diagnostics, including： pinhole camera imaging; thermo luminescent detector measurements; time-resolved scintillator measurements; and a curved mica spectrometer to register X-ray spectra. Both diffuse and collimated X-ray emission have been observed.. Diffuse emission occurs in bursts of X-rays; with up to 10^5 bursts per second, with up to 10^6 photons per burst during the discharge. Collimated X-ray emission appears in the form of beamlets directed normal to the cathodes surface with a very small angular divergence; with up to 104 bursts per second, and up to 1013 photons overall up to 20 h after discharge switch off. Based on these experimental results we propose a phenomenological model of processes.展开更多
0101974X 光二极管阴极灵敏度标定[刊]/黄天暄//强激光与粒子束.—2000,12(4).—455～458(D)在北京正负电子对撞机同步辐射装置3WIB 光束线上标定了一批 X 光二极管的灵敏度。应用一个简单的模型描述真空 X 光二极管光阴极发射光电子的...0101974X 光二极管阴极灵敏度标定[刊]/黄天暄//强激光与粒子束.—2000,12(4).—455～458(D)在北京正负电子对撞机同步辐射装置3WIB 光束线上标定了一批 X 光二极管的灵敏度。应用一个简单的模型描述真空 X 光二极管光阴极发射光电子的机制。同时,阴极表面粗糙度、氧和碳沾污可以解释金属光阴极的实际灵敏度曲线与模型预测的偏离。参5Y2000-62185-138 0101975采用曲线拟合优化方法确定 HSPICE IGBT 的动态参数=Determination of dynamic parameters for展开更多
文摘以锑化铯(Cs_(3)Sb)为代表的碱金属型半导体光阴极具有高量子效率、低电子发射度、光谱响应快等特点,可作为理想的新型电子发射源.然而Cs_(3)Sb中碱金属敏感于含氧气体,从而导致其结构不稳定,工作寿命低,影响电子发射效率.利用超薄层状的二维材料进行涂层保护Cs_(3)Sb基底,有望构建新型高性能光阴极材料,但目前仍然缺乏适合的二维材料,能够在保护基底同时维持低功函数(W)和高量子效率.近年来二维过渡金属碳/氮化物(MXene)材料逐渐成为研究热点,其灵活引入的悬挂键可以很好地调控MXene材料的结构和电子特性.本文系统构建了一系列M_(2)CT_(2)-Cs_(3)Sb异质结,基于第一性原理计算分析了过渡金属元素(M)、原子配比(M/C)、堆垛构型及悬挂键(T)等对其W的影响.研究表明,不同悬挂键类型对构建异质结的W影响显著,相对于其他悬挂键(—F/—O/—Cl/—S/—NH),带有—OH/—OCH_(3)悬挂键构成的M_(2)CT_(2)-Cs_(3)Sb异质结具有相对较低的W.利用差分电荷密度和能级矫正分析解释了异质结W的变化原因,即异质结界面电荷重新分布导致界面偶极方向不同,造成电子逸出的势垒不同.经过筛选后发现,M_(2)C(OH)_(2)(M=V,Ti,Cr)和M_(2)C(OCH_(3))_(2)(M=Ti,Cr,Nb)结构可以看作理想的涂层材料,尤其是V_(2)C(OH)_(2)-Cs_(3)Sb(W=1.602 e V)和Ti_(2)C(OCH_(3))_(2)-Cs_(3)Sb(W=1.877 e V).本研究不仅有助于深入理解MXene-Cs_(3)Sb异质结电子结构和光学性质,同时也为高性能光阴极材料的计算筛选提供参考依据.
文摘In this paper,nanosecond pulsed laser is introduced to selectively ablate away indium tin oxide film and metal film without destroying the underlying layers for fabricating organic light-emitting diodes.By varying density of energy,pulse number and width of the laser,the influence on morphology of the laser trenches of indium tin oxide and metal films are investigated.It is presented that uniform ablation trench can be obtained with 16 laser pulses at 0.15 J/cm^2 for aluminum film and 10 laser pulses at 0.65 J/cm^2 for indium tin oxide film.It is found that the characteristics of the organic light-emitting diodes prepared with laser ablation are almost the same as those of that prepared with conventional patterning method.
文摘X-ray emission from metal cathodes in glow discharge （current is up to 300 mA, voltage is 1,500-4,300 V） experiments in the spectral range from 700 eV to 6 keV has been observed. The effect has been seen with a variety of different metal cathodes （including AI, Sc, Ti, V, Ni, Nb, Zr, Mo, Pd, Ta, W, and Pt）, as well as with different gasses （including D2, H2, Kr, Ar, and Xe） at low pressure （3-10 Torr）. We present results from a variety of diagnostics, including： pinhole camera imaging; thermo luminescent detector measurements; time-resolved scintillator measurements; and a curved mica spectrometer to register X-ray spectra. Both diffuse and collimated X-ray emission have been observed.. Diffuse emission occurs in bursts of X-rays; with up to 10^5 bursts per second, with up to 10^6 photons per burst during the discharge. Collimated X-ray emission appears in the form of beamlets directed normal to the cathodes surface with a very small angular divergence; with up to 104 bursts per second, and up to 1013 photons overall up to 20 h after discharge switch off. Based on these experimental results we propose a phenomenological model of processes.
文摘0101974X 光二极管阴极灵敏度标定[刊]/黄天暄//强激光与粒子束.—2000,12(4).—455～458(D)在北京正负电子对撞机同步辐射装置3WIB 光束线上标定了一批 X 光二极管的灵敏度。应用一个简单的模型描述真空 X 光二极管光阴极发射光电子的机制。同时,阴极表面粗糙度、氧和碳沾污可以解释金属光阴极的实际灵敏度曲线与模型预测的偏离。参5Y2000-62185-138 0101975采用曲线拟合优化方法确定 HSPICE IGBT 的动态参数=Determination of dynamic parameters for
