15 February 2010 Theory of high field carrier transport and impact ionization in ZnO
Author Affiliations +
Proceedings Volume 7603, Oxide-based Materials and Devices; 760303 (2010) https://doi.org/10.1117/12.842562
Event: SPIE OPTO, 2010, San Francisco, California, United States
We present a full band Monte Carlo study of high field carrier transport and impact ionization properties of wurtzite ZnO. The proposed model is based on an accurate electronic structure calculated with a nonlocal empirical pseudopotential method and a phonon dispersion determined with density functional theory. The model includes the full details of the lowest eight conduction bands and the top six valence bands derived from the empirical pseudopotential method and a numerically calculated impact ionization transition rate based on a wave-vector dependent dielectric function. The carrier-phonon interaction is treated using the rigid pseudoion formalism, thus removing adjustable parameters such as deformation potential coefficients. Electric-field-induced interband transitions are included in the model by the direct solution of the time-dependent multiband Schrödinger equation. The hole ionization coefficient is found to be very low compared to the electron ionization coefficient. The low ratio of hole and electron ionization coefficients k = β/α holds the promise for high speed and low noise avalanche photodetection in the ultraviolet spectral range.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Francesco Bertazzi, Michele Penna, Michele Goano, Enrico Bellotti, "Theory of high field carrier transport and impact ionization in ZnO", Proc. SPIE 7603, Oxide-based Materials and Devices, 760303 (15 February 2010); doi: 10.1117/12.842562; https://doi.org/10.1117/12.842562

Back to Top