Optical properties of AsO−2-impurities in alkali halide crystals

✍ Scribed by F. J. Lohmeier; F. Fischer

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 529 KB
• Volume: 114
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2221140111

✦ Synopsis

Abstract

The optical properties of AsO^−^~2~‐ions dissolved in several alkali halide crystals are investigated. In optical absorption four bands are found, which belong to the long‐wavelength excitation of the impurity centre. In emission just one band is observed. Radiationless transitions between excited singlet states and the lowest lying B~1~‐triplet state are induced by a strong spin—orbit coupling. The ^3^B~1~‐state has a lifetime around 10^−4^ s, depending on the size of the anion of the host lattice. Above a temperature between 60 and 80 K (depending on the host lattice) radiationless transitions compete in the depopulation of the ^3^B~1~‐state. At the temperature of 4.2 K the long‐wavelength bands show a fine structure, that corresponds to the excitation of normal vibrations of the molecule. According to the strong electron–phonon‐coupling, no zero phonon lines are observed.