Luminescence excitation spectra and recombination radiation of diamond in the fundamental absorption region
Luminescence excitation spectra and recombination radiation of diamond in the fundamental absorption region
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金刚石基本吸收区的发光激发光谱和复合辐射
DOI：
10.1098/rspa.1964.0026
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发表时间：
1964
期刊：
影响因子：
--
通讯作者：
J. Male
中科院分区：
文献类型：
--
作者：
P. J. Dean;J. Male
获得了70余颗宝石级天然金刚石在量子能量区间5.0 ~ 7.5eV（2400 ~ 1600 Ω）的荧光激发谱。低于5.55 eV，存在与光学吸收光谱的某些组分直接相关的结构，但未发现与特征I型紫外吸收相关的结构。半导体金刚石的激发光谱包含一个强烈的温度依赖性组件，其结构对应于间接吸收边的初始结构。在绝缘金刚石中，这一成分相对较弱，并被一系列尖锐的带所掩盖，这些带也通常在吸收光谱中发现。所有菱形在80 °K下显示出接近5.486和5.538 eV的激发阈值，对应于吸收光谱的相对温度无关部分的低能量阈值。在5.55 eV以上，有一个规则间隔的激发带系统，其延伸到近7.0 eV。在半导体金刚石中，只有在低于100 °K的温度下才能观察到这些带，实验上的困难阻止了它们在6.0 eV以上存在的确认。这种结构被初步解释为激子和自由载流子的形成以及晶格缺陷应变场中的多声子发射过程。在高于约100 °K的温度下，半导体金刚石表现出最大值接近6.0 eV的宽激发带，这被认为与从受体中心到自由载流子或激子状态的直接跃迁有关。解释的光谱的金刚石的本征复合辐射中所观察到的峰的结果从声子辅助的激子的复合与晶格的热平衡。
Luminescence excitation spectra in the quantum energy interval 5.0 to 7.5 eV (2400 to 1600 Å) have been obtained for some seventy natural diamonds of gem quality. Below 5.55 eV, structure is present which is directly related to certain components of the optical absorption spectrum, but no structure is found which can be related to the characteristic type I ultra-violet absorption. The excitation spectra of semiconducting diamonds contain a strongly temperature-dependent component whose structure corresponds to the initial structure of the indirect absorption edge. In insulating diamonds, this component is relatively weak and is masked by a system of sharp bands, which are also commonly found in the absorption spectrum. All diamonds show excitation thresholds near 5.486 and 5.538 eV at 80 °K, corresponding with the low energy thresholds of the relatively temperature-independent part of the absorption spectrum. Above 5.55 eV there is a system of regularly spaced excitation bands which extends to nearly 7.0 eV. In semiconducting diamonds these bands can be observed only at temperatures below about 100 °K and experimental difficulties have prevented confirmation of their presence above 6.0 eV. The structure is tentatively interpreted in terms of exciton and free carrier formation together with multiphonon emission processes in the strain field of lattice defects. At temperatures above about 100 °K, semiconducting diamonds exhibit a broad excitation band with a maximum near 6.0 eV, which is thought to be associated with direct transitions from acceptor centres to free carrier or exciton states. An interpretation of the spectrum of the intrinsic recombination radiation of diamond is presented in which the observed peaks result from the phonon-assisted recombination of excitons in thermal equilibrium with the lattice.