Observation of a filled electronic state in the conduction band of InN

Abstract

We have investigated the electronic structure of InN epilayers grown by molecular beam epitaxy at different growth temperatures by hard X-ray photoemission spectroscopy. We observed filled electronic states in the conduction band of the InN films. Integral intensity of the filled electronic states developed with decreasing growth temperature. The decreasing growth temperature induced increasing oxygen incorporation into the InN films and increasing carrier concentration and optical band gap of the InN films. Therefore, the filled electronic states should be indicated the filling of carriers in the conduction band caused by oxygen incorporation and the present results support the Burstein-Moss shift.

Investigation of the Effect of Oxygen on the Near-Surface Electron Accumulation in Nonpolar m-Plane (101̄0) InN Film by Hard X-ray Photoelectron Spectroscopy

“…They are assigned to bulk oxygen component correlated with the electron carrier concentration in the InN films. 30,31) However, a small amount of an additional component located at the higher binding energy side (533.58 eV with FWHM of 1.4 eV) was observed at TOA of 15 as shown in Fig. 3(b), which began to appear when TOA was smaller than 29 .…”

“…It was assigned to surface oxygen component. 31) In order to investigate the variation of the bulk oxygen concentration as a function of TOA, all the O 1s spectra were normalized by In 3d 5=2 and N 1s core-level spectra. The O 1s intensities of the bulk oxygen component as a function of TOA were plotted in Fig.…”

Strong Correlation Between Oxygen Donor and Near-Surface Electron Accumulation in Undoped and Mg-Doped In-Polar InN Films

“…13) According to previous studies, oxygen incorporation into InN strongly modifies the valence band, and also donates electrons, which fill the conduction band. 14,15) In this study, we investigated the effect of incorporated impurity oxygen on the electronic structures of undoped (u-InN) and Mg-doped In-polar InN (InN:Mg) films by high-resolution angle-resolved HXPES.…”

“…The position of the valence band maximum (VBM) was determined by extrapolating a linear fit to the leading edge of the valence-band spectrum to the background level. 15,18,19) Figure 1(a) shows the valence band HXPES spectra for u-InN and InN:Mg at TOA of 79 . In the Figs.…”

“…They are assigned to bulk oxygen correlated with the electron carrier concentration in InN. 14,15) For HXPES, even TOA is 15 , the effective information depth is around 6 nm (3). That is why the surface adsorbed oxygen (about one layer) usually located at higher binding energy (533.…”