J–V Characteristic of p–n Structure Formed on n-GaAs Surface by Ar+ Ion Beam

Abstract

A highly defective ~10-nm-thick layer was fabricated in a high vacuum by 2.5 keV Ar⁺ ion bombardment of the n-GaAs surface. Valence band photoelectron spectra showed a p-type conductivity of the layer arising due to the high concentration of mechanically created point defects (p-centers). J–V characteristics measured ex situ for the structure consisting of the irradiated p-layer on the n-type substrate revealed a diode effect. Analysis of the data attributes the effect to the formation of a specific p–n junction. Thereby, we demonstrated that Ar⁺ ion bombardment of the n-GaAs surface results in that a nanostructure with the p–n junction properties is formed. The p–n junction under consideration seems to deserve further study and possible application since it can be formed in high-vacuum clean conditions directly by exposure to a low-energy Ar⁺ ion beam without wet lithography.