@article{1753, 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.}, author = {Songmuang, Rudeeson and Georgios Katsaros and Monroy, Eva and Spathis, Panayotis N and Bougerol, Catherine and Mongillo, Massimo and De Franceschi, Silvano}, journal = {Nano Letters}, number = {9}, pages = {3545 -- 3550}, publisher = {American Chemical Society}, title = {{Quantum transport in GaN/AlN double-barrier heterostructure nanowires}}, doi = {10.1021/nl1017578}, volume = {10}, year = {2010}, }