Determination of polar C-plane and nonpolar A-plane AlN/GaN heterojunction band offsets by X-ray photoelectron spectroscopy

Abstract

We have directly measured the valence-band offsets (VBOs) of wurtzite C-plane and A-plane AlN/GaN heterojunctions by X-ray photoelectron spectroscopy. The VBOs were determined to be 0.82 AE 0.15 and 0.63 AE 0.15 eV for the C-plane and A-plane AlN/GaN heterojunctions, respectively. The discrepancy in VBOs of heterojunctions with different orientations is mainly due to the spontaneous polarization effect. The VBO of the nonpolar heterojunction is closer to the intrinsic value since the A-plane samples show no polarization effects.

Interface characterization of atomic layer deposited Al2O3 on m‐plane GaN

“…The extracted larger CBO between thermal ALD‐Al 2 O 3 and m‐plane GaN is beneficial for electronic applications. Recently, a VBO of 0.63 eV between a‐plane AlN and a‐plane GaN has been reported . Assuming a band gap of 6.2 eV for AlN, a CBO of 2.17 eV was obtained which was comparable to ALD‐Al 2 O 3 and m‐plane GaN.…”

Design of Multilayered Porous Aluminum Nitride for Supercapacitor Applications

“…Figure f shows the XPS spectra of AlN, which further proved the existence of the Al–N bond. The peak at ≈73.8 eV of the Al 2p spectrum corresponds to the Al–N bond originating from AlN. − There is no peak corresponding to the Al–C bond in the Al 2p spectrum, which means that carbon exists in an independent form and increases the electrical conductivity of AlN.…”

Improvement of TE-polarized emission in type-II InAlN–AlGaN/AlGaN quantum well*

“…VBO InN/GaN and VBO AlN/GaN denote the valence band offsets of InN/GaN and AlN/GaN, set as 0.62 eV and −0.82 eV, respectively. [14,15] The Coulomb potential energy is obtained by solving the Poisson equation in the whole region of LED, while the Schrödinger equation is only solved in the active region. In the calculation, the finite difference method is adopted with a 1 Å interval.…”