Phosphorescence theory

In fact, an important advance in the phosphorescence theory was realized by Wiedemann in 1889, stating that a phosphor exists in two forms, a stable one, A, and an unstable one, B. Light absorption brings along conversion of form A to B, which then returns to A emitting light. This hypothesis was in agreement with the exponential decay law as postulated years before by Becquerel, but who did not provide any information about the nature of both forms [5],... 

R. S. Becker, Theory and Interpretation of Fluorescence and Phosphorescence , J. Wiley, New York, 1969. 

Becker, R. S. Theory and interpretation of fluorescence and phosphorescence. New York Wiley-Interscience 1969. 

Pauli principle, 45-47,178-182, 284-287 Pauli spin matrices, 96 P branch, 171-173,218,303 Peanuts, 320 Perpendicular band, 259, 265 Perturbation, spectroscopic, 283 Perturbation theory, 35-38,102 degenerate, 36-38 for nuclear motion, 149-159 time-dependent, 110-114 Phase, 13 Phenol, 225 Phosphorescence, 128 Phosphorous trichloride, structure of, 222, 223... 

Patemo-Buchi reactions, 238-255 Pauli s exclusion principle, 19,24,31,40 Perturbation, external heavy atom, 145 Perturbation theory time dependent, 53 Phantom triplet, 229 Phase-shift method, 309, 311 a-phosphorescence, 129 -phosphorescence, 157 Phosphorescence... 

One of the most of important applications of quadratic response theory, pertaining to spin-orbit properties, is the calculation of the spin-orbit induced dipole moment (phosphorescence, see section 7), which can be derived from the residue... 

In contrast to polyenes the aromatic molecules exhibit not only the Ti — So absorption, but also the longlived T — So emission, which gives rise to phosphorescence phenomena of rigid solvents and crystals. This is another important field of applications of spin-orbit quadratic response theory. Such calculations refer to lifetimes, transition moments, oscillator strengths and polarization directions for the radiative decay of molecular triplet states. These quantities may either be averaged over the triplet levels or refer to specific triplet spin sublevels depending on the conditions for the relevant experimental measurements. 

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