Band offset

About: Band offset is a research topic. Over the lifetime, 2446 publications have been published within this topic receiving 53450 citations.

Electron wave-function spillover in self-assembled InAs/InP quantum wires

Abstract: Charge confinement in InAs/ InP self-assembled quantum wires is studied experimentally using photoluminescence in pulsed magnetic fields and theoretically using adiabatic theory within the effective-mass approximation, taking into account the strain in the samples. We show both experimentally and theoretically that, in spite of the large conduction band offset, the electron wave function is significantly spilled out of the wire in the wire height direction for thin wires. Furthermore, for a wire thickness of up to 8 monolayers, the electron spillover is inversely related to the wire height. These effects are due to the large zero point energy of the electron. As the wire becomes thicker, the decrease in confinement energy is reflected in a reduction of the electron wave-function extent.

Band offsets and interfacial properties of cubic CdS grown by molecular-beam epitaxy on CdTe(110)

Abstract: Etude par emission photoelectronique. Observation d'une attenuation exponentielle de l'emission du niveau de cœur 4d de Te en fonction de l'eapisseur de la couche de CdS, ainsi que la persistence du cliche de diffraction des electrons de haute energie de reflexion de type substrat. Ceci demontre que les couches sont epitaxiques. Analyse de la structure de bande et de la discontinuite de la bande de valence de CdS

III-N-V low-bandgap nitrides and their device applications

Abstract: Four families of III-N-V compounds for electronic and optoelectronic applications are presented: InNAsP/InP, GaInNAs/GaAs, Ga(In)NP/GaP and GaInNP/GaAs. InNAsP/GaInAsP quantum wells grown on InP are superior for long-wavelength microdisc lasers (and so expected for edge-emitting lasers), as compared to GaInAs/GaInAsP quantum wells, because of the larger conduction band offset from the addition of a small amount of nitrogen (0.5% to 1%) in the InAsNP quantum wells. GaInNAs/GaAs heterostructures emitting at 1.3 µm at room temperature have stimulated much interest in 1.3 µm vertical-cavity surface-emitting lasers. Here we report the use of GaInNAs as the base of a heterojunction bipolar transistor (HBT), which exhibits a lower turn-on voltage than HBTs with the usual GaInAs base. Incorporating a small amount of N in GaNxP1-x alloys leads to a direct bandgap behaviour of GaNP, and red light-emitting diodes based on a GaNP/GaP double heterostructure grown directly on (100) GaP substrates have been fabricated. Finally, incorporating N into GaInP barriers in a quantum well is shown to lower the conduction band offset, and GaInNP/GaAs could be potentially ideally suited for npn HBTs.

Band structure and valence-band offset of HfO2 thin film on Si substrate from photoemission spectroscopy

Abstract: Synchrotron radiation photoemission spectroscopy and optical transmission spectrum measurements have been performed on an HfO2 thin film grown on a Si(100) substrate to determine the band structure of the HfO2/Si stack. The result shows a valence-band offset of 2.5 eV and a conduction-band offset of 2.2 eV for the HfO2/Si interface. The Schottky barrier height between Au and HfO2 is obtained from current density–voltage measurement. The characterization reveals that the dominant conduction mechanism in the region of low field under gate injection is Schottky emission. The energy-band diagram of an Au–HfO2–Si MOS stack was obtained from these results.