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High-field transport and electroluminescence in ZnS phosphor layers

TitleHigh-field transport and electroluminescence in ZnS phosphor layers
Publication TypeJournal Article
Year of Publication1998
AuthorsDür, M., S. M. Goodnick, S. S. Pennathur, J. F. Wager, M. Reigrotzki, and R. Redmer
JournalJournal of Applied Physics
Date Published1998
Keywordsconduction bands, electroluminescence, high field effects, II-VI semiconductors, impact ionisation, manganese, Monte Carlo method, phosphors, semiconductor thin films, thin film devices, zinc compounds

A full-band Monte Carlo simulation of the high-field electron transport in the ZnS phosphor layer of an alternating-current thin-film electroluminescent device is performed. The simulation includes a nonlocal empirical pseudopotential band structure for ZnS and the relevant scattering mechanisms for electrons in the first four conduction bands, including band-to-band impact ionization and impact excitation of Mn²⁺ luminescent centers. The steady-state electron energy distribution in the ZnS layer is computed for phosphor fields from 1 to 2 MV/cm. The simulation reveals a substantial fraction of electrons with energies in excess of the Mn²⁺ impact excitation threshold. The computed impact excitation yield for carriers transiting the phosphor layer exhibits an approximately linear increase with increasing phosphor field above threshold. The onset of Mn²⁺ impact excitation coincides with the onset of band-to-band impact ionization of electron-hole pairs which prevents electron runaway at high electric fields.

Short TitleJ. Appl. Phys.