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Photoluminescence of GaAs0.973Sb0.022N0.005 is investigated at different temperatures and pressures. Both the alloy band edge and the N-related emissions, which show different temperature and pressure dependences, are observed. The pressure coefficients obtained in the pressure range 0-1.4GPa for the band edge and N-related emissions are 67 and 45meV/GPa, respectively. The N-related emissions shift to a higher energy in the lower pressure range and then begin to redshift at about 8.5GPa. This redshift is possibly caused by the increase of the X-valley component in the N-related states with increasing pressure. 相似文献
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采用热丝化学气相沉积技术制备了一系列处于不同生长阶段的薄膜样品,用原子力显微镜系 统地研究生长在单晶硅衬底和玻璃衬底上薄膜表面形貌的演化.按照分形理论分析得到:在 玻璃衬底上的硅薄膜以零扩散随机生长模式生长;而在单晶硅衬底上,薄膜早期以有限扩散 生长模式生长,当膜厚超过某一临界厚度时转变为零扩散随机生长模式.岛面密度与膜厚的 依赖关系表明,在临界厚度时硅衬底和玻璃衬底上的岛面密度均出现了极大值.Raman谱的测 量证实,玻璃衬底上薄膜临界厚度与非晶/微晶相变之间存在密切的关系.不同的衬底材料直 接影响反应
关键词:
生长机制
微晶硅薄膜
表面形貌
热丝化学气相沉积 相似文献
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数学在科学技术中的地位和作用 总被引:2,自引:0,他引:2
数学是一切科学的得力助手和工具,它有时由于其它科学的促进而发展,有时也超前发展,领先的发展最终定能获得应用.任何一门科学的发展若离开了数学,就不能准确地刻画客观事物变化的状态,更不能从已知推出未知,因而也就削弱了科学预见的可能性和精确度.如果没有数学对其它科学的渗透,也就不能使人类的认识真正上升为理性. 相似文献
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Luminescent properties of Tm3+-doped GdYTaO4 are studied for exploring their potential applications in temperature and pressure sensing.Two main emission peaks from 3H4→3H6 transition of Tm3+are investigated.Intensity ratio between the two peaks evolves exponentially with temperature and has a highest sensitivity of 0.014 K?1 at 32 K.The energy difference between the two peaks increases linearly with pressure increasing at a rate of 0.38 meV/GPa.Intensity ratio between the two peaks and their emission lifetimes are also analyzed for discussing the pressure-induced variation of the sample structure.Moreover,Raman spectra recorded under high pressures indicate an isostructural phase transition of GdYTaO4 occurring at 4.46 GPa. 相似文献
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Role of amorphous silicon domains of Er^3+ emission in the Er—doped hydrogenated amorphous silicon suboxide film 下载免费PDF全文
An investigation on the correlation between amorphous Si (a-Si) domains and Er^{3+} emission in the Er-doped hydrogenated amorphous silicon suboxide (a-Si:O:H) film is presented. On one hand, a-Si domains provide sufficient carriers for Er^{3+} carrier-mediated excitation which has been proved to be the highest excitation path for Er^{3+} ion; on the other hand, hydrogen diffusion from a-Si domains to amorphous silicon oxide (a-SiO_x) matrix during annealing has been found and this possibly decreases the number of nonradiative centres around Er^{3+} ions. This study provides a better understanding of the role of a-Si domains on Er^{3+} emission in a-Si:O:H films. 相似文献
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用硅离子注入方法制备的纳米硅的拉曼散射研究 总被引:1,自引:0,他引:1
在直角散射配置下测量了纳米硅样品的拉曼散射谱及其退火温度的关系。结果表明,在800℃以下退火的样品只观察到单晶硅衬底的光学声子模,在900℃以上退火,才观察到纳米硅的特征拉曼散射峰。在1200℃下退火后,纳米硅的特征拉曼散射峰消失,观察到类似于非晶硅的光学声子特征峰,可能表示纳米硅不能承受这样的高温热退火。这些结果进一步证实了光致发光谱的结果。 相似文献
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Influence of Polar Pressure Transmission Medium on the Pressure Coefficient of Excitonic Interband Transitions in Monolayer WSe_2 下载免费PDF全文
The influence of the pressure transmission medium(PTM)on the excitonic interband transitions in monolayer tungsten diselenide(WSe_2)is investigated using photoluminescence(PL)spectra under hydrostatic pressure up to 5GPa.Three kinds of PTMs,condensed argon(Ar),1:1 n-pentane and isopentane mixture(PM),and4:1 methanol and ethanol mixture(MEM,a PTM with polarity),are used.It is found that when either Ar or PM is used as the PTM,the PL peak of exciton related to the direct K-K interband transition shows a pressure-induced blue-shift at a rate of 32±4 or 32±1 meV/GPa,while it turns to be 50±9meV/GPa when MEM is used as the PTM.The indirect A-K interband transition presents almost no shift with increasing pressure up to approximatel.y 5 GPa when Ar and PM are used as the PTM,while it shows a red-shift at the rate of-17±7meV/GPa by using MEM as the PTM.These results reveal that the optical interband transitions of monolayer WSe_2 are very sensitive to the polarity of the PTM.The anomalous pressure coefficient obtained using the polar PTM of MEM is ascribed to the existence of hydrogen-like bonds between hydroxyl in MEM and Se atoms under hydrostatic pressure. 相似文献
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