In this paper, we have studied the strain, band-edge, and energy levels of cubic InGaAs quantum dots (QDs) surrounded by GaAs. It is shown that overall strain value is larger in InGaAs-GaAs interfaces, as well as in smaller QDs. Also, it is proved that conduction and valence band-edges and electron-hole levels are size dependent; larger QD sizes appeared to result in the lower recombination...

Cr(1-x)Al(x) exhibits semiconducting behavior for x = 0.15-0.26. This Letter uses hard x-ray photoemission spectroscopy and density functional theory to further understand the semiconducting behavior. Photoemission measurements of an epitaxial Cr(0.80)Al(0.20) thin film show several features in the valence band region, including a gap at the Fermi energy (E(F)) for which the valence band edge i...

This paper is a review article covering our work in recent years on PbTe and the alloy semiconductor CdXPbl-,Te. It shows how measurements of the transport and optical properties of these materials support (1) the two valence band model for PbTe in which the principal light mass band is highly non-parabolic and the secondary heavy mass band is parabolic and (2) a value for the Hall-anisotropy f...

Realization of group IV heterostructure devices requires the accurate measurement of the energy band offsets in Si/Si12xGex and Si/Si12x2yGexCy heterojunctions. Using admittance spectroscopy, we have measured valence-band offsets in Si/Si12xGex heterostructures and conduction-band and valence-band offsets in Si/Si12x2yGexCy heterostructures grown by solid-source molecular-beam epitaxy. Measured...

Auger processes involving the filling of holes in the valence band are thought to make important contributions to the low-energy photoelectron and secondary electron spectrum from many solids. However, measurements of the energy spectrum and the efficiency with which electrons are emitted in this process remain elusive due to a large unrelated background resulting from primary beam-induced seco...

The valence band offset (VBO) of wurtzite indium nitride/strontium titanate (InN/SrTiO3) heterojunction has been directly measured by x-ray photoelectron spectroscopy. The VBO is determined to be 1.26 ± 0.23 eV and the conduction band offset is deduced to be 1.30 ± 0.23 eV, indicating the heterojunction has a type-I band alignment. The accurate determination of the valence and conduction band o...

Metal-oxide-semiconductor capacitors were fabricated on type-II staggered gap strained-Si/strained-Ge heterostructures epitaxially grown on relaxed SiGe substrates of various Ge fractions. Quasistatic quantummechanical capacitance-voltage (CV) simulations were fit to experimental CV measurements to extract the band alignment of the strained layers. The valence-band offset of the strained-Si/str...

Abnormal increase of low frequency flicker noise in analog nMOSFETs with gate oxide in valence band tunneling domain is investigated. In 15Å oxide devices, valence-band electron tunneling from Si substrate to poly-gate occurs at a positive gate voltage and results in the splitting of electron and hole quasi Fermi-levels in the channel. The excess low frequency noise is attributed to electron an...