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Schlagwörter:
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Zusammenfassung:
Luminescence in Hg2Cl2, crystals excited with UV light is investigated in the spectral region 0.8–2.25 eV. Measurements are performed on as-grown samples and on samples previously exposed to UV light at RT. Six emission bands are found which depend on the concentration of the photochemical entities produced by irradiation of the crystals at RT. It is concluded that infra-red (IR) luminescence of Hg2Cl2 originates from crystal defects. The observed emission bands are tentatively attributed to the emission of (HgCIxBr3−x)− and (HgClxBr4−x)2− complexes formed with residual Br impurities. Centres responsible for IR Hg2Cl2 emissions are excited: (i) via excitons of Hg2Cl2, (ii) via excited states of isolated Hg2Br2 molecules, and (iii) resonantly through the excitation bands of defect centres.
