A general purpose sub-keV X-ray facility at the Stanford Synchrotron Radiation Laboratory

Tirsell, K.G.; Karpenko, V. P.

doi:10.1016/0168-9002(90)90113-k

Cited by 54 publications

(43 citation statements)

References 7 publications

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“…19 Data was collected both by using largely bulk-sensitive total fluorescence yield (TFY), which has a penetration of ≈ 100 nm, and by the more surface sensitive total electron yield (TEY), which has a penetration of ≈ 10 nm. 20 …”

Section: Methodsmentioning

confidence: 99%

Understanding and control of bipolar self-doping in copper nitride

Fioretti

Schwartz

Vinson

et al. 2016

Journal of Applied Physics

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Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu3N thin films. Room temperature Hall effect and Seebeck effect measurements show n-type Cu3N with an electron density of 1017 cm−3 for low growth temperature (≈ 35 °C) and p-type with a hole density between 1015 cm−3 and 1016 cm−3 for elevated growth temperatures (50 °C to 120 °C). Mobility for both types of Cu3N was ≈ 0.1 cm2/Vs to 1 cm2/V. Additionally, temperature-dependent Hall effect measurements indicate that ionized defects are an important scattering mechanism in p-type films. By combining X-ray absorption spectroscopy and first-principles defect theory, we determined that VCu defects form preferentially in p-type Cu3N while Cui defects form preferentially in n-type Cu3N; suggesting that Cu3N is a compensated semiconductor with conductivity type resulting from a balance between donor and acceptor defects. Based on these theoretical and experimental results, we propose a kinetic defect formation mechanism for bipolar doping in Cu3N, that is also supported by positron annihilation experiments. Overall, the results of this work highlight the importance of kinetic processes in the defect physics of metastable materials, and provide a framework that can be applied when considering the properties of such materials in general.

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Section: Methodsmentioning

confidence: 99%

Understanding and control of bipolar self-doping in copper nitride

Fioretti

Schwartz

Vinson

et al. 2016

Journal of Applied Physics

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“…The beamline uses bend magnet radiation and a spherical grating monochromator. 11 XAS experiments were conducted with an energy resolution of ∼0.2 eV at the carbon K-edge.…”

Section: Instrumentationmentioning

confidence: 99%

Chemically Transformable Configurations of Mercaptohexadecanoic Acid Self-Assembled Monolayers Adsorbed on Au(111)

et al. 2004

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Carboxyl-terminated self-assembled monolayers (SAMs) are commonly used in a variety of applications, with the assumption that the molecules form well-ordered monolayers. In this work, near-edge X-ray absorption fine structure measurements verify that well-ordered monolayers can be formed using acetic acid in the solvent. Disordered monolayers with unbound molecules present in the film result using only ethanol. A stark reorientation occurs upon deprotonation of the end group by rinsing in a KOH solution. This reorientation of the end group is reversible with tilted-over, hydrogen-bound carboxyl groups while the carboxylate ion end groups are upright. C(1s) photoemission shows that SAMs formed and rinsed with acetic acid in ethanol have protonated end groups, while SAMs formed without acetic acid have a large fraction of carboxylate-terminated molecules.

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“…NEXAFS measurements were performed at the bending magnet beamline 8-2 of SSRL 52 , with a ring current of 500 mA, operating the spherical grating monochromator with the 500 l mm À 1 grating at intermediate (B0.3 eV) resolution. The toroidal refocusing optics provided a near circular beam cross-section of about 1 mm FWHM (full width at half maximum) in diameter (footprint horizontally was 1-3 mm FWHM pending on the incidence angle).…”

Section: Methodsmentioning

confidence: 99%

Ultra-high mobility transparent organic thin film transistors grown by an off-centre spin-coating method

et al. 2014

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Organic semiconductors with higher carrier mobility and better transparency have been actively pursued for numerous applications, such as flat-panel display backplane and sensor arrays. The carrier mobility is an important figure of merit and is sensitively influenced by the crystallinity and the molecular arrangement in a crystal lattice. Here we describe the growth of a highly aligned meta-stable structure of 2,7-dioctyl[1]benzothieno [3,2-b][1]benzothiophene (C8-BTBT) from a blended solution of C8-BTBT and polystyrene by using a novel offcentre spin-coating method. Combined with a vertical phase separation of the blend, the highly aligned, meta-stable C8-BTBT films provide a significantly increased thin film transistor hole mobility up to 43 cm 2 Vs À 1 (25 cm 2 Vs À 1 on average), which is the highest value reported to date for all organic molecules. The resulting transistors show high transparency of 490% over the visible spectrum, indicating their potential for transparent, high-performance organic electronics.

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A general purpose sub-keV X-ray facility at the Stanford Synchrotron Radiation Laboratory

Cited by 54 publications

References 7 publications

Understanding and control of bipolar self-doping in copper nitride

Understanding and control of bipolar self-doping in copper nitride

Chemically Transformable Configurations of Mercaptohexadecanoic Acid Self-Assembled Monolayers Adsorbed on Au(111)

Ultra-high mobility transparent organic thin film transistors grown by an off-centre spin-coating method

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