Improved hydrogen detection sensitivity in N-polar GaN Schottky diodes

Yu Lin Wang, F. Ren, U. Zhang, Q. Sun, C. D. Yerino, T. S. Ko, Y. S. Cho, I. H. Lee, J. Han, S. J. Pearton

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58 Citations (Scopus)


Pt/GaN Schottky diodes fabricated on m -plane (N-polar) layers grown on sapphire exhibit much larger responses to dilute concentrations (4% in N2) of hydrogen at room temperature than comparable Ga-polar devices. This is consistent with previous density functional theory indicating a very high affinity of hydrogen for the N-face surface of GaN. The rectifying current-voltage characteristics of N-face diodes make a transition to more Ohmic-like behavior after hydrogen exposure, leading to very large (∼ 106) maximum percentage changes in current relative to Ga-face (∼10%) or AlGaN/GaN heterostructure diodes (∼170%). The strong affinity of the N face of GaN for hydrogen also leads to a slower recovery of these diodes when hydrogen is removed from the ambient.

Original languageEnglish
Article number212108
JournalApplied Physics Letters
Issue number21
Publication statusPublished - 2009
Externally publishedYes

Bibliographical note

Funding Information:
The work at UF was partially supported by ONR Grant No. N000140710982 monitored by Igor Vodyanoy, by NSF DMR Grant No. 0400416, and the State of Florida, Center of Excellence in Nano-Bio Sensors.

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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