Band offset

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

Experimental determination of band offset energies between Zr silicate alloy dielectrics and crystalline Si substrates by XAS, XPS and AES and ab initio theory: a new approach to the compositional dependence of direct tunneling currents

Abstract: XPS, AES and XAS studies of non-crystalline Zr silicate alloys have identified the band edge electronic structure, and the compositional dependence of valence and conduction band offset energies. These results are integrated into a two band tunneling model for a conduction band with localized Zr 4d* followed by extended Si 3s* states with composition-independent conduction band offset energies, respectively, of /spl sim/1.4 and 3.2 eV. The model predicts a minimum tunneling current for ZrO/sub 2/ content in the mid-alloy composition range.

Study of the valence band offsets between InAs and InAs 1-x Sb x alloys

Abstract: InAs/InAs1-xSbx strain-balanced superlattices (SLs) on GaSb are a viable alternative to the well-studied InAs/Ga1-xInxSb SLs for mid- and long-wavelength infrared (MWIR and LWIR) laser and photodetector applications, but the InAs/InAs1-xSbx SLs are not as thoroughly investigated Therefore, the valence band offset between InAs and InAs/InAs1-xSbx, a critical parameter necessary to predict the SL bandgap, must be further examined to produce InAs/InAs1-xSbx SLs for devices operational at MWIR and LWIR wavelengths The effective bandgap energies of InAs/InAs1-xSbx SLs with x = 028 - 040 are designed using a three-band envelope function approximation model Multiple 05 μm-thick SL samples are grown by molecular beam epitaxy on GaSb substrates Structural characterization using x-ray diffraction and atomic force microscopy reveals excellent crystalline properties with SL zero-order peak full-width-half-maximums between 30 and 40 arcsec and 20 x 20 μm2 area root-mean-square roughnesses of 16 - 27 A Photoluminescence (PL) spectra of these samples cover 5 to 8 μm, and the band offset between InAs and InAs/InAs1-xSbx is obtained by fitting the PL peaks to the calculated values The bowing in the valence band is found to depend on the initial InAs/InSb valence band offset and changes linearly with x as CEv_bowing = 158x - 062 eV when an InAs/InAs1-xSbx bandgap bowing parameter of 067 eV is assumed A fractional valence band offset, Qv = ΔEv/ΔEg, of 175 ± 003 is determined and is practically constant in the composition range studied

Triple-band offset hybrid antenna using shaped reflector

Abstract: A triple-band offset hybrid antenna having a shaped reflector is disclosed. The triple-band offset hybrid antenna includes: a shaped reflector reflecting a K/Ku bands RF signals received from a satellite to focus an energy of the K/Ku band RF signals on a focal line and reflecting a Ka band RF transmitting signal; and a triple-band active phased feed array receiving the reflected K/Ku bands RF signals from the shaped reflector and radiating the Ka band RF transmitting signal to the shaped reflector, wherein the triple-active feed array including Ka/K bands feed array for transceiving Ka/K bands RF signal and a Ku band feed array for receiving a Ku band RF signal.

Energy band alignment of atomic layer deposited HfO2 on epitaxial (110)Ge grown by molecular beam epitaxy

Abstract: The band alignment properties of atomic layer HfO2 film deposited on epitaxial (110)Ge, grown by molecular beam epitaxy, was investigated using x-ray photoelectron spectroscopy. The cross-sectional transmission electron microscopy exhibited a sharp interface between the (110)Ge epilayer and the HfO2 film. The measured valence band offset value of HfO2 relative to (110)Ge was 2.28 ± 0.05 eV. The extracted conduction band offset value was 2.66 ± 0.1 eV using the bandgaps of HfO2 of 5.61 eV and Ge bandgap of 0.67 eV. These band offset parameters and the interface chemical properties of HfO2/(110)Ge system are of tremendous importance for the design of future high hole mobility and low-power Ge-based metal-oxide transistor devices.

Band Alignment and Band Gap Characterization of La 2 O 3 Films on Si Substrates Grown by Radio Frequency Magnetron Sputtering

Abstract: La2O3 films are grown on Si (100) substrates by the radio-frequency magnetron sputtering technique. The band alignment of the La2O3/Si heterojunction is analyzed by the x-ray photoelectron spectroscopy. The valence-band and the conduction-band offsets of La2O3 films to Si substrates are found to be 2.40±0.1 and 1.66±0.3eV, respectively. Based on O 1s energy loss spectrum analysis, it can be noted that the energy gap of La2O3 films is 5.18±0.2 eV, which is confirmed by the ultra-violet visible spectrum. According to the suitable band offset and large band gap, it can be concluded that La2O3 could be a promising candidate to act as high-k gate dielectrics.