The factors limiting the conductivity of fluorine-doped tin dioxide (FTO) produced via atmospheric pressure chemical vapor deposition are investigated. Modeling of the transport properties indicates that the measured Hall effect mobilities are far below the theoretical ionized impurity scattering limit. Significant compensation of donors by acceptors is present with a compensation ratio of 0.5, indicating that for every two donors there is approximately one acceptor. Hybrid density functional theory calculations of defect and impurity formation energies indicate the most probable acceptor-type defects. The fluorine interstitial defect has the lowest formation energy in the degenerate regime of FTO. Fluorine interstitials act as singly charged acceptors at the high Fermi levels corresponding to degenerately n-type films. X-ray photoemission spectroscopy of the fluorine impurities is consistent with the presence of substitutional F O donors and interstitial F i in a roughly 2:1 ratio in agreement with the compensation ratio indicated by the transport modeling. Quantitative analysis through Hall effect, X-ray photoemission spectroscopy, and calibrated secondary ion mass spectrometry further supports the presence of compensating fluorine-related defects.

Plasma treatment was used as a new method to enhance the photocatalytic performance of a hydrophobic polymer photocatalyst.

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Large-area transparent conductive few-layer graphene electrode in GaN-based ultra-violet light-emitting diodes Appl. Phys. Lett. 99, 143101 (2011) Efficiency droop behaviors of the blue LEDs on patterned sapphire substrate J. Appl. Phys. 110, 073102 (2011) Effect of organic bulk heterojunction as charge generation layer on the performance of tandem organic light-emitting diodes J. Appl. Phys. 110, 074504 (2011) Self-heating and athermal effects on the electroluminescence spectral modulation of an AlGaInP light-emitting diode J. Appl. Phys. 110, 073103 (2011) Improved light output of GaN-based vertical light emitting diodes using SiO2 nanotube arrays and transparent metal oxide current conduction layer Appl. Phys. Lett. 99, 131111 (2011) Additional information on Appl. Phys. Lett.

The Raman spectra of quaternary InAs x Sb y P1−x−y epitaxial layers nominally lattice-matched to (1 0 0) n-type InAs substrates are reported. The phonon peaks are identified for alloys covering a wide composition range extending into the miscibility gap. Three-mode behaviour was obtained across part of the composition range. InP-like longitudinal optical (LO) and transverse optical (TO) phonons were observed over the entire compositional range, but InAs-like LO phonons were only observed at high arsenic concentrations and no InSb-like TO phonons were observed. Disorder-related phonon peaks were obtained for alloy compositions within the miscibility gap.