Determination of Band Structures of InN/GaN Interfaces by Synchrotron Radiation Hard X-ray Photoemission Spectroscopy

We have determined the valence band discontinuities of InN/Mg: GaN and InN/Si: GaN heterostructures by hard x-ray photoemission spectroscopy. InN thin films were grown by pulsed laser deposition method and streaky highenergy electron diffraction pattern was observed, indicating that good crystalline InN films were grown. The value of valence band discontinuity for InN/Mg: GaN is as small as 0.3 eV, while that for InN/Si: GaN is 1.4 eV. The fact that the InN/Mg: GaN interface has the small energy barrier suggests that InN is very promising for the interlayer between transparent conductive layers and Mg: GaN in light emitting diode structures.