Acousto-optical effect in the luminescence excitation spectrum of HgI2

A study of the photoluminescence excitation spectrum in a crystal of mercury diiodide is reported. Each of the two luminescence bands peaking at 543 and 572–575 nm investigated was found to have its own excitation spectrum. The excitation spectrum of the 575-nm line in the long-wavelength doublet band has been observed to be sensitive to strong ultrasound vibrations and preliminary irradiation of the sample by 590-nm light. This line is associated with radiative recombination of photocarriers at intrinsic point defects (vacancies or iodine and mercury interstitials) located close to dislocations. The binding energy of the photosensitive center to a dislocation was estimated from the change in the excitation spectrum. Fiz. Tverd. Tela (St. Petersburg) 41, 1965–1968 (November 1999)