Strong Electric Monopulses in Nonuniformly Doped Nitride Films under Negative Differential Conductivity

The excitation of the strong nonlinear monopulses of space charge waves in the transversely non-uniform n-GaN and n-InN films is investigated theoretically. The stable numerical algorithms have been used for nonlinear 3D simulations. The monopulses of the strong electric field of durations 3 - 10 ps can be excited. The bias electric field should be chosen slightly higher than the threshold values for observing the negative differential conductivity. The doping levels should be moderate for the nitrides 10
¹⁶
-10
¹⁷
cm
^-3
. The electric monopulses of high peak values are excited from input small electric pulses. These nonlinear monopulses in the films differ from the domains of strong electric fields in the bulk semiconductors.