Quantum transport in GaN/AlN double-barrier heterostructure nanowires Journal Article

Author(s): Songmuang, Rudeeson; Katsaros, Georgios; Monroy, Eva; Spathis, Panayotis N; Bougerol, Catherine; Mongillo, Massimo; De Franceschi, Silvano
Article Title: Quantum transport in GaN/AlN double-barrier heterostructure nanowires
Abstract: We investigate electronic transport in n-i-n GaN nanowires with and without AlN double barriers. The nanowires are grown by catalyst-free, plasma-assisted molecular beam epitaxy enabling abrupt GaN/AlN interfaces as well as longitudinal n-type doping modulation. At low temperature, transport in n-i-n GaN nanowires is dominated by the Coulomb blockade effect. Carriers are confined in the undoped middle region, forming single or multiple islands with a characteristic length of ∼100 nm. The incorporation of two AlN tunnel barriers causes confinement to occur within the GaN dot in between. In the case of a 6 nm thick dot and 2 nm thick barriers, we observe characteristic signatures of Coulomb-blockaded transport in single quantum dots with discrete energy states. For thinner dots and barriers, Coulomb-blockade effects do not play a significant role while the onset of resonant tunneling via the confined quantum levels is accompanied by a negative differential resistance surviving up to ∼150 K.
Keywords: Quantum transport; III-N nanowires; nanowire heterostructures; tunneling barriers
Journal Title: Nano Letters
Volume: 10
Issue 9
ISSN: 1530-6992
Publisher: American Chemical Society  
Date Published: 2010-09-08
Start Page: 3545
End Page: 3550
Sponsor: This research was partly funded by the Agence Nationale de la Recherche through the COHESION project. G.K. acknowledges further support from the Deutsche Forschungsgemeinschaft (Grant KA 2922/1-1)
DOI: 10.1021/nl1017578
Open access: yes (repository)