Valence-band ordering in ZnO

Valence-Band Ordering in ZnO

Effects of strain on the valence band structure and exciton-polariton energies in ZnO

Markus R. Wagner,1,2,* Gordon Callsen,1 Juan S. Reparaz,1,2 Ronny Kirste,1,3 Axel Hoffmann,1 Anna V. Rodina,4 André Schleife,5,6,7,† Friedhelm Bechstedt,6,7 and Matthew R. Phillips8 1Institute of solid state physics, Technische Universität Berlin, 10623 Berlin, Germany 2ICN2 Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, 08193 Bellaterra (Barcelona), Spain 3Department of Material ...

Direct determination of the band offset in ALD-grown ZnO/hydrogenated amorphous silicon heterojunctions from XPS valence band spectra

The chemical composition and band alignment at the heterointerface between ALD-grown zinc oxide (ZnO) and hydrogenated amorphous silicon (a-Si:H) is investigated using monochromatized X-ray photoelectron spectroscopy. A new approach for obtaining the valence band offset EV is developed, which consists in fitting the valence band (VB) spectrum obtained for a-Si:H with a thin ZnO overlayer as th...

Valence band and core-level analysis of highly luminescent ZnO nanocrystals for designing ultrafast optical sensors

Highly luminescent ZnO:Na nanocrystals of size ~2 nm were synthesized using a improved sol-lyophilization process. The surface analysis such as survey scan, core-level and valence band spectra of ZnO:Na nanocrystals were studied using x-ray photoelectron spectroscopy (XPS) to establish the presence of Na + ions. The observed increase in band gap from 3.30 (bulk) to 4.16 eV (nano), is attributed...

Ferromagnetic ordering in Mn-doped ZnO nanoparticles

Zn1 - x Mn x O nanoparticles have been synthesized by hydrothermal technique. The doping concentration of Mn can reach up to 9 at% without precipitation or secondary phase, confirmed by electron spin resonance (ESR) and synchrotron X-ray diffraction (XRD). Room-temperature ferromagnetism is observed in the as-prepared nanoparticles. However, the room-temperature ferromagnetism disappears after ...