Abstract
We report the fabrication of nanostructured p-i-n photodiodes based on GaN. Each device comprises arrays of ∼200 nm diameter and 520 nm tall nanopillars on a 1 μm period, fabricated by e-beam lithography. Strong rectifying behavior was obtained with an average reverse current per nanopillar of 5 fA at -5 V. In contrast to conventional GaN diodes, nanostructured devices reproducibly show ideality factors lower than 2. Enhanced tunneling through sidewall surface states is proposed as the responsible mechanism for this behavior. Under backillumination, the quantum efficiency in nanostructured devices is partly limited by the collection efficiency of holes into the nanopillars.
Original language | English (US) |
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Article number | 221104 |
Journal | Applied Physics Letters |
Volume | 93 |
Issue number | 22 |
DOIs | |
State | Published - 2008 |
Funding
The authors would like to thank Y. Bai, and D. Hoffman for their assistance during the nanostructured device fabrication. The authors also acknowledge the Fulbright Association and the Spanish Ministry of Education and Science for supporting one of the authors (J.L.P.).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)