A.E. Belyaev

Abstract: . Present paper studies double barrier resonant tunnelling diodes (DB-RTD) based on GaN/AlGaN heterostructures, grown by plasma-assisted molecular beam epitaxy (PA-MBE). Tunnel (current-voltage, I (cid:150) V ) and capacitance (capacitance-voltage, C(cid:150)V ) spectroscopy meas- urements were performed at the temperature range from 4.2 to 300 K. It has been found that measured characteristics of DB-RTD have complex nonlinear behavior and reveal the current discontinuities of I (cid:150) V curves. The features can be explained by the existence of polarization fields and interface defects. These effects strongly influence on the potential profile of the DB- RTD heterostructures. To understand physics of the processes, numerical simulations of the given structures, using a model based on real-time Green(cid:146)s functions, have been performed. Comparative analysis of experimental and numerical data showed that the current instability and nonlinearity of characteristics of the nitride based DB-RTD can be connected with trap- ping the electrons onto interfacial and dislocation states in these heterostructures.