When biased on the negative differential resistance regime, electroluminescence (EL) is emitted from planar GaAs heterostructure Gunn diodes due to the recombination of electrons in the device channel with holes that are generated by impact ionisation when the Gunn domains reach the anode edge. This EL forms non-uniform patterns whose intensity shows short-range intensity variations in the dire...

The GaN material parameters relevant to the negative di€erential resistance (NDR) devices are discussed, and their physical models based on the theoretical predictions and experimental device characteristics are introduced. Gunn diode design criteria were applied to design the GaN NDR diodes. A higher electrical strength of the GaN allowed operation with higher doping ( 10 cmÿ3) and at a higher...

OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Heikki Holmberg Name of the dissertation Spin-dependent transport in Mn Doped GaAs and GaN diodes Manuscript submitted 16.11.2007 Manuscript revised 4.2.2008 Date of the defence 14.3.2008 Monograph Article dissertation (summary + original articles) Faculty Faculty of Electronics, Commu...

We present experimental evidence and physics-based simulations of the lock-on effect in high-voltage GaAs avalanche diodes . The triggering is initiated by steep voltage ramp applied to diode in-series 50 ? load. After subnanosecond switching reversely biased remains conducting state for whole duration pulse (dozens nanoseconds). There no indication p-n junction recovery that commonly expected ...