Low-Temperature Recombination Luminescence in Alkali Halide Crystals
Low-Temperature Recombination Luminescence in Alkali Halide Crystals
复制标题
碱金属卤化物晶体的低温复合发光
DOI：
10.1103/physrev.136.a1296
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发表时间：
1964
期刊：
影响因子：
--
通讯作者：
M. Kabler
中科院分区：
文献类型：
--
作者：
M. Kabler
碱金属卤化物晶体在低温X射线激发下观察到的发光被认为是由于在理想晶格中的辐射电子-空穴复合。在KCl中，发射光谱是单带，而在KBr、KI和NaCl中有两个带。在含有自陷空穴的晶体中，电子过剩缺陷如$F$中心的光激发导致电子转移到空穴，并发射与直接由X射线照射激发的相同的复合发光。如果空穴被优先取向，则KCl和KBr的光激发发光表现出所涉及的跃迁的部分偏振特性。复合发光的起源是通过这些偏振特性，连同结果的光激发和漂白光谱，温度依赖性，激发效率，和杂质的独立性。这项工作的相关性，从激发$F$中心的电子隧穿过程中讨论了从一个基本的观点。漂白的$F$和${F}^{\ensuremath\'}}$中心通过吸收的复合发光被证明是一个潜在的重要因素，在确定的各种中心的增长率在高能量照射。
Luminescence observed upon low-temperature x-ray excitation of alkali-halide crystals has been identified as due to radiative electron-hole recombination in the perfect lattice. In KCl the emission spectrum is a single band, while in KBr, KI, and NaCl there are two bands. In crystals containing self-trapped holes, optical excitation of electron-excess defects such as $F$ centers causes transfer of electrons to holes with emission of recombination luminescence identical to that excited directly by x-ray irradiation. If the holes have been preferentially oriented, the optically excited luminescence from KCl and KBr exhibits partial polarization characteristic of the transitions involved. The origin of the recombination luminescence is revealed through these polarization properties, together with results on optical excitation and bleaching spectra, temperature dependence, excitation efficiency, and impurity independence. The relevance of this work to the process of electron tunneling from excited $F$ centers is discussed from an elementary point of view. The bleaching of $F$ and ${F}^{\ensuremath{'}}$ centers through the absorption of recombination luminescence is shown to be a potentially important factor in determining the growth rates of the various centers during high-energy irradiation.