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Cambridge, MA, United States

Banerjee P.,University of Maryland University College | Chen X.,University of Maryland University College | Gregorczyk K.,University of Maryland University College | Henn-Lecordier L.,Cambridge NanoTech, Inc. | Rubloff G.W.,University of Maryland University College
Journal of Materials Chemistry

We demonstrate high current rectification in a new system comprising 30 nm of hydrated vanadium pentoxide and 100 nm of zinc oxide (V2O 5·nH2O-ZnO) thin film structures. The devices are prepared using a low temperature (<150 °C), all atomic layer deposition process. A key element in the rectifying properties comes from anomalous p-type conductivity in V2O5 - an otherwise well known n-type semiconductor. Experimental evidence points to protonic (H+) conductivity due to intercalated water in V2O5 as the source for p-type behaviour, while the ZnO is known to be electronically n-type. Thus, the diode behaves as a novel, mixed mode ionic-electronic rectifier. Further, we show that the diode characteristics are strongly dependent on the electrode material in contact with V2O5·nH 2O. A high Ion/Ioff ratio (598) at ± 2 V is obtained for oxygen-free Pt electrodes, whereas a low Ion/I off ratio (19) is obtained for oxygen-rich ITO electrodes, suggesting the deleterious effects of oxygen atom reactivity to device characteristics. © 2011 The Royal Society of Chemistry. Source

Gregorczyk K.,University of Maryland University College | Henn-Lecordier L.,University of Maryland University College | Henn-Lecordier L.,Cambridge NanoTech, Inc. | Gatineau J.,Air Liquide | And 2 more authors.
Chemistry of Materials

A recently reported ruthenium molecule, bis(2,6,6-trimethyl- cyclohexadienyl)- ruthenium, has been developed and characterized as a precursor for atomic layer deposition (ALD) of ruthenium. This molecule, which has never been reported as an ALD precursor, was developed to address low growth rates, high nucleation barriers, and undesirable precursor phases commonly associated with other Ru precursors such as RuCp and Ru(EtCp) 2.The newly developed precursor has similar vapor pressure to both RuCp and Ru(EtCp) 2 but offers significant improvement in stability as evaluated by thermogravimetric analysis and differential scanning calorimetry. In an ALD process, it provides good self-limiting growth, with a 0.5 Å/cycle growth rate under saturated dose conditions in a temperature between 250 and 300 C°. Furthermore, the precursor exhibits considerably better nucleation characteristics on SiO 2, TiO 2, and H-terminated Si surfaces, compared to RuCp 2 and Ru(EtCp) 2. © 2011 American Chemical Society. Source

Cambridge NanoTech, Inc. | Date: 2010-02-26

A gas deposition system (

Cambridge NanoTech, Inc. | Date: 2011-06-17

An improved precursor vaporization device and method for vaporizing liquid and solid precursors having a low vapor pressure at a desired precursor temperature includes elements and operating methods for injecting an inert gas boost pulse into a precursor container prior to releasing a precursor pulse to a reaction chamber. An improved ALD system and method for growing thin films having more thickness and thickness uniformity at lower precursor temperatures includes devices and operating methods for injecting an inert gas boost pulse into a precursor container prior to releasing a precursor pulse to a reaction chamber and for releasing a plurality of first precursor pulses into a reaction chamber to react with substrates before releasing a different second precursor pulse into the reaction chamber to react with the substrates.

Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase I | Award Amount: 94.82K | Year: 2010

Atomic Layer Deposition (ALD) has been widely studied for water permeation barriers for flexible OLED displays. Inorganic films of approximately 100nm have been demonstrated to reduce the water vapor transmission rate (WVTR) to 6e-7 g/m^2/d at room temperature. However, these films crack at less than 2% strain. Inorganic ALD films cannot withstand the required 5% strain until their thickness is reduced to 5nm at which point the WVTR becomes unacceptably high. Hybrid inorganic/organic ALD films have demonstrated enhanced strain resilence but few chemistries have thus far been studied, and their optimized WVTR and mechanical flexibility have yet to be determined. We propose to investigate several classes of new precursor chemicals to generate hybrid inorganic/organic films to assess their applicability for encapsulating flexible OLED displays. Once the best chemistry has been identified and optimized, we will leverage our companies history of successful scaling to commercial manufacturing of ALD processes.

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