Changes in surface state density due to chlorine treatment in GaN Schottky ultraviolet photodetectors

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A chlorination surface treatment was used to reduce the surface density of states of a n -type GaN surface, which improves the Schottky performances of the resultant metal-semiconductor contact. Using capacitance-frequency measurement, the surface state density of the chlorine-treated GaN surface was about one order less than that without chlorination treatment. The dark current of the chlorine-treated GaN ultraviolet photodetectors (UV-PDs) is 1.5 orders of magnitude lower than that of those without chlorination treatment. The products of quantum efficiency and internal gain of the GaN Schottky UV-PDs without and with chlorination treatment under conditions of -10 V reverse bias voltage at a wavelength of 330 nm were 650% and 100%, respectively. The internal gain in chlorine-treated GaN UV-PDs can therefore be reduced due to a decrease in the surface state density.

Original languageEnglish
Article number094504
JournalJournal of Applied Physics
Issue number9
Publication statusPublished - 2008 May 26


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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