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Radiative and Non‐Radiative Processes of Localized Impurity Centers in Alkali Halides: KBr:Ag −
Author(s) -
Shimanuki S.
Publication year - 1988
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221480123
Subject(s) - excitation , arrhenius equation , atomic physics , activation energy , radiative transfer , photon energy , halide , impurity , emission intensity , alkali metal , chemistry , photon , physics , optics , inorganic chemistry , organic chemistry , quantum mechanics
Abstract The C and A emissions in KBr:Ag − are measured in detail between 11.2 and 300 K. At 11.2 K, excitation in the peak position of the C band exhibits the C emission but it hardly produces A emission. Changing the excitation position to the higher energy side of the C band peak, the A emission is produced a little. The intensity (emitted photon number) ratio of the A to C emission, η, shows an excitation photon‐energy dependence and changes over three orders within both sides of the C band. Increasing the temperature, η itself increases as a whole and its excitation photon‐energy dependence weakens and disappears at about 80 K. The values of η in the lower energy edge show an activation process of Arrhenius type over four orders above around 45 K, whose activation energy is 0.076 eV, and below 30 K, another activation process of the same type with an activation energy of 0.0025 eV. A few causes of the exciting energy dependence of η at low temperatures are considered and the mechanism due to the dynamical nonradiative transition is proposed.