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本文报道了氢化非晶碳薄膜在2.9-4.5eV光激发下的发光谱。它的光致发光谱是无结构的不对称宽带,半宽度约为0.8eV。在低于3.56eV的光激发下,谱带的峰值能量随激发能量的降低明显红移。在安德森带结构和指数分布的带尾态密度的基础上,考虑了尾态中粒子的两种跃迁过程,实验的PL谱就可得到解释。并用这个简单模型计算了这种材料的光致发光谱特征。 相似文献
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采用化学气相沉积方法,以金做催化剂,在Si (100)衬底上制备了掺AlZnO纳米线阵列.扫描电子显微镜(SEM)表征发现ZnO纳米线的直径在30nm左右.X射线衍射(XRD)图谱上只存在ZnO的(002)衍射峰,说明ZnO纳米线沿c轴择优取向.掺AlZnO纳米线阵列的室温光致发光(PL)谱中出现了3个带边激子发射峰:373nm,375nm,389nm.运用激子理论推算出掺AlZnO纳米线的禁带宽度为3.343eV ,束缚激子结合能为0.156eV;纯ZnO纳米线阵列PL谱中3个带边激子发射
关键词:
光致发光
化学气相沉积(CVD)
激子
ZnO纳米线阵列 相似文献
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本文用红外光致发光方法研究了InP中与C带有关的深能级的性质和起源。峰值位于价带上0.34eV(77K)附近的宽谱带普遍存在于不同方式生长的InP外延层和掺Sn与不掺杂的衬底中,且与P空位引起的复合缺陷有关。 通过红外光致发光强度对温度的依赖关系得到C带的热激活能为0.17eV。这刚好与采用σ函数来描述深能级的Locovsky模型相吻合,光谱线型与温度猝灭的量子力学位形坐标模型拟合,得到与C带有关的深能级hv=0.02eV,S=8。 相似文献
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在电容耦合式PECVD系统中,以CH4和H2为气源,通过控制H2的流量制备了一系列氢化非晶碳膜(a-C:H)样品。利用傅里叶变换红外光谱(FTIR)、光致发光谱(PL)和吸收谱对a-C:H膜的结构及光学性质进行了研究。结果表明:氢稀释可以在一定程度上减少碳的sp^2团簇的形成,增大它的光学带隙,并改变薄的微结构。与此同时,光致发光峰随郑 光学带隙的增大而蓝移;当光学带隙增大2.72eV时,出现了2.4eV(绿光)和2.97eV(蓝光)组成的发光峰。 相似文献
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利用MOCVD在Al_2O_3(0001)衬底上制备InGaN/GaN MQW结构蓝光LED外延片。以400 mW中心波长405 nm半导体激光器作为激发光源,采用自主搭建的100~330 K低温PL谱测量装置,以及350~610 K高温PL测量装置,测量不同温度下PL谱。通过Gaussian分峰拟合研究了InGaN/GaN MQW主发光峰、声子伴线峰、n-GaN黄带峰峰值能量、相对强度、FWHM在100~610 K范围的温度依赖性。研究结果表明:在100~330 K温度范围内,外延片主发光峰及其声子伴线峰值能量与FWHM温度依赖性,分别呈现S与W形变化;载流子的完全热化分布温度约为150 K,局域载流子从非热化到热化分布的转变温度为170~190 K;350~610 K高温范围内,InGaN/GaN MQW主发光峰峰值能量随温度变化满足Varshni经验公式,可在MOCVD外延生长掺In过程中,通过特意降温在线测PL谱,实时推算掺In量,在线监测外延片生长。以上结果可为外延片的PL发光机理研究、高温在线PL谱测量设备开发、掺In量的实时监测等提供参考。 相似文献
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采用射频等离子体辅助分子束外延(RF plasma-assisted MBE)系统生长非故意掺杂GaN和p型GaN,并且通过室温和低温光致发光(PL)谱测试研究了材料的发光特性及与杂质态的关系,对于GaN外延层出现的黄带发光进行分析。结果表明,富Ga条件下生长的GaN材料特性要优于富N生长的材料;非故意掺杂的富Ga样品中出现的黄带发光(YL)与GaN中生成能最低的氮空位(VN)缺陷有关;不同的Mg掺杂浓度对样品的PL特性有较大的影响;结合Hall效应测量结果,认为在Mg重掺杂的样品中出现的黄带发光,与GaN的自补偿效应以及重掺杂导致的晶体质量下降有关。 相似文献
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通过对掺锰磷化铟的1.18eV辐射的频率响应谱(FRS)及辐射峰随激发强度的位移的研究得到了明确的证据,确认这个光致发光辐射的施主受主对(DAP)复合的性质。一个和Mn2+相关的复合跃迁过程被提出用以解释有关的实验结果。 相似文献
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Si/SiNx/SiO2多层膜的光致发光 总被引:1,自引:0,他引:1
采用射频磁控溅射法,制备了具有强光致可见发光的纳米Si/SiNx/SiO2多层膜,利用傅立叶红外吸收(FTIR)谱,光致发光(PL)谱对其进行了研究。用260nm光激发得到的PL谱中观察到高强度的392nm(3.2eV)和670nm(1.9eV)光致发光峰,分析认为它们分别来自于缺陷态≡Si-到价带顶和从导带底到缺陷态≡Si-的辐射跃迁而产生的光致激发辐射复合发光。PL谱中只有370nm(3.4eV)处发光峰的峰位会受退火温度的影响,结合FTIR谱认为370nm发光与低价氧化物—SiOx(x<2.0)结合体有密不可分的关系。当SiO2层的厚度增大时,发光强度有所增强,800℃退火后出现最强发光,认为具有较大SiO2层厚度的Si/SiNx/SiO2结构多层膜更有利于退火后形成Si—N网络,能够得到更高效的光致发光。用量子限制-发光中心(QCLC)模型解释了可能的发光机制,并建立了发光的能隙态(EGS)模型。 相似文献
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Blue Photoluminescence of Oxidized Films of Porous Silicon 总被引:1,自引:0,他引:1
V. V. Filippov P. P. Pershukevich V. V. Kuznetsova V. S. Khomenko L. N. Dolgii 《Journal of Applied Spectroscopy》2000,67(5):852-856
It is found that the films of n
+-type porous silicon of low (10–50%) porosity exhibit photoluminescence in the region 400–500 nm after a 5-month storage in an air atmosphere. The spectrum of blue photoluminescence of the least porous but strongly oxidized films has maxima at 417, 435, and 465 nm. The same spectrum structure manifests itself upon the introduction of an Er3+- and Yb3+-containing complex. The mechanisms of blue photoluminesence are discussed. 相似文献
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用CH4,H2和NH3为反应气体,利用等离子体增强热丝化学气相沉积在沉积有碳膜的Si衬底上制备了a-C:N:H纳米尖端,并用扫描电子显微镜和微区Raman光谱仪对碳膜和纳米尖端进行了表征。结果表明:Raman谱中含有与碳和氮相关的峰,且纳米尖端的Raman谱比碳膜的Raman谱有很强的荧光背景。Raman谱中的峰说明沉积的碳膜和纳米尖端是a-C:N:H薄膜和a-C:N:H尖端。a-C:N:H纳米尖端的Raman谱中强荧光背景的产生表明其在激发光源照射的过程中发射了强荧光,对a-C:N:H纳米尖端产生强荧光的机理进行了探讨。 相似文献
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T. V. Voloshina T. N. Zavaritskaya I. V. Kavetskaya V. A. Karavanskii D. A. Romashov 《Journal of Applied Spectroscopy》2002,69(2):275-278
Samples of porous silicon have been produced and investigated for the first time by the method of anodizing in a modified iodinecontaining electrolyte. It is shown that the addition of iodine to the electrolyte, all other things being constant, substantially influences the formation of porous silicon and leads to the occurrence of photoluminescence in poroussilicon layers on highly doped substrates of silicon of the n
+type. The morphology of the surface of the produced poroussilicon samples has been investigated and a marked decrease in the inhomogeneity scale as compared to the nonluminescent porous silicon produced without iodine under the same conditions has been detected. Investigation of the dependence of the spectral properties of photoluminescence on the density of the anodizing current has shown that with increase in the current density the maximum of the photoluminescence spectrum shifts to the shortwave region and the halfwidth of the photoluminescence spectrum decreases. 相似文献
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E. M. Shishonok L. Trinkler S. V. Leonchik B. Berzinya 《Journal of Applied Spectroscopy》2008,75(4):567-575
Under high pressure and temperature conditions, we have obtained samples of thulium-activated cubic boron nitride in the form
of micropowders, ceramics, and polycrystals activated by thulium in the presence of aluminum. We studied the cathodoluminescence
(CL), photoluminescence (PL), and photoluminescence excitation spectra of the samples. In the luminescence spectra we observe
structured bands with maxima at ∼370, ∼475, ∼660, and ∼ 800 nm, assigned to electronic transitions in the triply charged thulium
ions. We have established that the most efficient method for excitation of “blue” luminescence at ∼475 nm for thulium ions
in cBN is excitation by an electron beam. The cBN samples synthesized in the presence of Al have photoluminescence spectra
with a more complex structure compared with samples not containing Al, with the band of dominant intensity at about 660 nm.
Hypothetically, this is a consequence of incorporation of thulium ions into the crystalline phases cBN and AlN, which are
equally likely to be formed during synthesis. The observed photoluminescence spectrum of the indicated samples is the superposition
of the photoluminescence spectra of the Tm3+ ions located in the crystal fields of cBN and AlN of different symmetries. The presence in the photoluminescence excitation
spectra (at 450, 490, and 660 nm) of structure, with features at wavelengths shorter than the excited photoluminescence, suggests
a nonresonant mechanism for its excitation. We have established that luminescence of Tm3+ ions is less intense than for other rare earth elements incorporated into cubic boron nitride.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 547–555, July–August, 2008. 相似文献
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用光致发光激发(PLE)谱分析吸收谱的亚结构。实验样品是共熔法制备的CdSeS量子点玻璃,量子点的生长时间分别为2h和4h,高分辨透射电子显微镜(HRTEM)分析得到样品中量子点的平均直径分别为3.6nm和3.8nm。在室温下对样品进行了光吸收谱和光致发光激发谱研究。光吸收谱显示了量子尺寸效应,光致发光激发谱中低能端有两个明显的峰。考虑价带简并以及电子与空穴之间的相互作用,通过理论分析和数值计算,得到1S3/2-1Se和2S3/2-1Se的跃迁能量及其随量子点半径的变化,由此确认光致发光激发谱中的两个峰分别为1S3/2-1Se和2S3/2-1Se跃迁。 相似文献
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