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Role of adsorbed water in inducing electron accumulation in InN

MetadataDetails
Publication Date2019-12-09
JournalJournal of Applied Physics
AuthorsQi Wang, Siddharth Joshi, Nicholas Smieszek, Vidhya Chakrapani
InstitutionsRensselaer Polytechnic Institute
Citations10

Nominally undoped indium nitride (InN) is known to have an electron accumulation layer on its surface, and prior studies have shown this layer to be sensitive to chemical species. However, the exact roles of these species and the underlying mechanism of eāˆ’ accumulation layer formation are not clear. In this work, it is shown that ambient adsorbed water on the InN surface strongly enhances the eāˆ’ accumulation layer formed due to intrinsic surface states. Desorption of ambient physisorbates leads to a decrease in band bending, an increase in work function in undoped InN, and the observation of a p-type Mott-Schottky behavior in Mg:doped InN. The underlying mechanism of this surface-adsorbed water interaction may be through a process called ā€œsurface transfer doping,ā€ which has previously been reported in hydrogenated diamond and other semiconductors such as GaN and ZnO.