The Excitation Wavelength Dependence of Adenine Cation Single Crystal Luminescence

The excitation wavelength dependence of luminescence measured in adenine cation crystals at 77 K is reported. The observed variations of all the luminescence parameters exhibit a marked correlation with a changing penetration depth of the excitation light. The alterations of luminescence intensity, vibronic structure of emission spectra, emission polarization and phosphorescence decay were attributed mainly to a variable contribution of the emission from local excited states which correspond to a different trap ensembles in the crystal bulk and near the surface, respectively.