Evaluation of the photoresponse in wurtzite GaN photoconductive switches is presented based on kinetic Monte Carlo simulations. The focus is on electron transport physics and assessment of high frequency operation. The role of GaN bandstructure, Pauli exclusion, and treatment of internal fields based on the Fast Multipole Method (FMM), are all comprehensively included. The implementation was validated through comparisons of velocity-field characteristics for GaN with computational results in the literature. Photocurrent widths of less than ~ 7 ps for the 1 μm device can be expected, which translates into a 100 GHz upperbound. Photocurrent pulse compression below the laser full width at half maxima (FWHM) at high applied fields are predicted based on the interplay of space-charge effects and the negative differential velocity characteristics of GaN.
|Journal||Journal of Applied Physics|
|State||Published - Apr 2021|