Bi‐stable behaviour in GaN‐based resonant tunnelling diode structures

Abstract

We have investigated the vertical electronic transport in AlN/GaN/AlN double barrier structures grown by plasma‐assisted molecular‐beam epitaxy, with AlN barrier thickness of 0.5 nm and a GaN well thickness varying from 0.5 nm to 2 nm. Two different current levels were observed in different devices in all the samples, the highest one being attributed to leakage through dislocations, and the lower one to tunnelling transport through the barriers. In the sample with a well thickness of 0.5 nm, we observed a bi‐stable behaviour, with an apparent negative differential resistance in the current‐voltage characteristic when scanning the voltage from negative to positive bias. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Room temperature negative differential resistance characteristics of polar III-nitride resonant tunneling diodes

“…Various groups have studied Al X Ga ͑1−X͒ N / GaN ͑X Ն 0.70͒ double-barrier ͑DB͒ resonant tunneling structures. [3][4][5][6][7][8][9][10] However, in these studies, after the initial I-V measurements, the NDR degraded leaving dominant exponential I-V behavior in the consequent ones. Recently, we have shown reliable and reproducible NDR in GaN RTDs employing low aluminum content active layer design.…”

Advanced AlGaN/GaN Resonant Tunneling Diode on Silicon Substrate for Negligible Scattering and Polarization effects

“…First one is dominant at low temperature whereas, last one is dominant at high temperature. Piezoelectric polarization charge occurs due to the strain at the Al x Ga 1-x N-GaN interface which degrades the performance of RTD by providing asymmetric current voltage characteristics [2,3]. High aluminum content (x 0.70) leads barrier designs leading to large lattice-mismatch at the hetero-interface [4][5][6][7][8] resulting piezoelectric polarization charge at the interface.…”

AlN/GaN double-barrier resonant tunneling diodes grown by metal-organic chemical vapor deposition

“…4 First works on III-Nitride RTDs has led debatable results with low reproducibility and stability. 5,6 Previous works report RTDs with P/V from 32 ͑for AlN/GaN heterostructure on sapphire͒ 7 to 2 ͑for Al 0.7 Ga 0.3 N / GaN heterostructure on free-standing c-GaN͒. 8 However, these RTDs were grown by molecular beam epitaxy ͑MBE͒, and no studies yet can demonstrate RT NDR at RTDs grown by metal-organic chemical vapor deposition ͑MOCVD͒.…”