Quantized Electron Accumulation States in Indium Nitride Studied by Angle-Resolved Photoemission Spectroscopy

Abstract

Electron accumulation states in InN have been measured using high resolution angle-resolved photoemission spectroscopy (ARPES). The electrons in the accumulation layer have been discovered to reside in quantum well states. ARPES was also used to measure the Fermi surface of these quantum well states, as well as their constant binding energy contours below the Fermi level E(F). The energy of the Fermi level and the size of the Fermi surface for these quantum well states could be controlled by varying the method of surface preparation. This is the first unambiguous observation that electrons in the InN accumulation layer are quantized and the first time the Fermi surface associated with such states has been measured.

How Indium Nitride Senses Water

“…We observe circular electron pockets at the Γ-points, corresponding to a previously observed 2DEG in InN. 17,25 Cuts along the ΓK (k x ) and ΓM (k y ) high symmetry directions in Fig. 2 16 : a heavy-hole (HH), a light-hole (LH) and a split-off hole band (CH), with the valence band (VB) maximum at -1.36 eV.…”

“…16 A quantum well (QW) forms, hosting a two-dimensional electron gas (2DEG) with quantized energy levels. 17 This QW is highly sensitive to surface adsorbates, which modulate the 2DEG and surface charge carrier concentration, resulting in a macroscopic resistance change in the semiconductor. 12 In addition to its robust yet electrically responsive surface properties, the biocompatible nature and thermal stability of InN make it an archetypal candidate for sensing applications -a rarely studied field for this material.…”

High‐Mobility Two‐Dimensional Electron Gas at InGaN/InN Heterointerface Grown by Molecular Beam Epitaxy

“…The discrepancy between these two values might be due to the unexpected InGaN accumulation of electrons on the surface that was not taken into account during the simulation. In addition, as was reported for InN,42 the energy level differences between the Fermi level and the corresponding subbands induced by electron accumulation on the surface were 511 and 797 meV, respectively, which are much larger than those that originate from 2DEG. Therefore, we exclude the possibility that the electron accumulation on the heterostructure surface induces a subband occupation.…”

Effect of catalyst nanoparticle size on growth direction and morphology of InN nanowires

“…9 Sometimes, it happens that both the VLS and VS processes concurrently take place in one crystal growth process. 9,10 InN, as an important III-V compound semiconductor with a direct band gap energy of about 0.7 eV at room temperature 11 and surface electron accumulation, 12 has attracted growing attention owing to its good performances in semiconductor optoelectronic, 13 Tera-Hertz emission devices, 14,15 as well as high-speed heterojunction FETs. 16 At present, plentiful InN nanostructures, including NWs, 3 nanorods, 17 nanotubes, 18 nanobelts, 19 nanonetworks 20 and nanoflowers 21 have been reported.…”