Electron-beam-induced modifications of electronic properties in GaN-based quantum well structures

The electronic properties of (In,Ga)N/GaN quantum wells depend significantly on the exposure dose of low-energy electron-beam irradiation (LEEBI), which is used, e.g. for cathodoluminescence (CL). For unintentionally doped structures, we observe an LEEBI-induced activation of donors and acceptors. Thus, the resistivity of the layers is not varied, while the quantum efficiency and optical transition energy increase significantly under LEEBI. The electric-field distribution in a p-n structure is changed towards the flat-band conditions during LEEBI, indicating electron-beam-induced passivation of acceptors in the p-type layer.