Controlled synthesis of nanostructures and thin films by CVD and PLD using real-time diagnostics, including 2D layered materials (metal chalcogenides, graphene), carbon nanostructures (nanotubes, nanohorns), oxide thin films and heterostructures with atomically-engineered interfaces, as well as hybrid organic/inorganic perovskite films. Wet/dry assembly of these materials into optoelectronic device architectures (photovoltaic, photocatalytic, ultrafast spectroscopy, environmental testing) over multiple length scales. Visit the Nanomaterials Characterization page to learn about related characterization capabilities available to CNMS users.
- For 2D materials including graphene, metal chalcogenides and 1D materials including SWNT, MWNT, vertically aligned nanotube arrays (VANTAs) on substrates
- Several CVD systems are available:
- CVD system in a 3"-i.d. tube furnace (1200°C) with pressures down to ~ 1 Torr and fast-acting electro-pneumatic valves for switching source gases; integrated time-resolved reflectivity diagnostics and remote video imaging of growth dynamics. The system is in proximity of tunable ns-lasers for laser diagnostics of CVD processes, or for combined laser-CVD (e.g. for doping of nanotubes during CVD growth, or laser-generation of catalyst nanoparticles for CVD, etc.).
- Thermal CVD of single and multiwall carbon nanotubes, nanotube arrays, and nanotube patterns at atmospheric pressure and flow.
- Metal Chalcogenide CVD systems – Several systems specific to different materials (such as GaSe, MoS2, MoSe2, WS2, WSe2) specialize in the growth of 2D crystals by vapor transport growth from mixed evaporated powders.
- Time-resolved reflectivity (TRR) of nanomaterial growth kinetics by CVD
For aligned nanotube arrays, utilizes stabilized HeNe laser beam reflectivity Fabry-Perot interference oscillations and attenuation to directly measure the height of vertically-aligned nanostructure arrays during growth – for growth rate, catalyst assessment.
- ns-Laser Vaporization Synthesis of SWNTs, NWs, NPs
SWNTs and nanowires are produced by pulsed Nd:YAG laser-irradiation (30 Hz, Q-switched or free-running) of composite pellets in a 2" tube furnace with variable pressure control. Excimer laser ablation of materials into variable pressure background gases is used for nanoparticle generation in proximity of ns-laser diagnostics.
- fs-laser synthesis of metal or alloy nanoparticles by through-thin-film ablation – nm’s thin metal films deposited on transparent substrates are ablated by single fs-laser pulses. Gated ICCD imaging or Rayleigh scattering diagnostics are used to observe the nanoparticle cloud in vacuum or background gases. Samples are collected on TEM grids for analysis.
- High-power ms-laser vaporization bulk production of nanomaterials
SWNH (single-wall carbon nanohorns), nanotubes, nanoparticles and nanowires in grams quantities are produced by robotically-scanned 600W Nd:YAG laser-irradiation (1064 nm) of targets at controlled pressure in various atmospheres (including CVD gases) at <1200°C inside a 3" tube furnace. Rapid sampling capability (located outside of the CNMS).
Oxide Thin Film Pulsed-Laser Deposition – Complex Heterostructures with high-pressure RHEED
- Oxide thin film and complex oxide heterostructure PLD
Oxide thin films and complex oxide superlattice growth by pulsed-laser deposition (including magnetic, ferroelectric, superconducting materials; strain-engineered heterostructures) with in-situ high-pressure RHEED for atomic-layer control.
- Complex heterostructures combining PLD, RF-sputtering, and laser heating
Growth of thin films of oxide and metallic compounds combining oxide PLD and RF sputtering to create composites and superlattice heterostructures. This growth system incorporates laser heating, and pressure control to rapidly change growth conditions, along with in-situ RHEED.
- Oxide Target Synthesis
Standard facilities for milling, drying, pressing, and sintering of oxide materials, to prepare PLD targets.
Laser Processing and Interactions with Materials
- Laser processing of materials under controlled atmospheres
High-power pulsed or CW (600W) Nd:YAG (1064 nm) for rapid thermal processing, or pulsed CVD growth in hydrocarbon gas atmospheres. In addition, pulsed nanosecond or femtosecond irradiation of materials for laser cutting, thinning, patterning, reduction, nanostructuring (SERS, LIPSS), or surface modification with X-Y-Z control.
- Laser induced forward transfer
- Gated ICCD imaging and spectroscopy of laser vaporization processes
Intensified CCD-array photography (5-ns resolution) and intensified, gated diode-array spectroscopy of laser interactions and laser ablation processes in controlled atmospheres. Secondary pulsed probe laser illumination for LIF, LII, LIP, scattering, and broadband OAS.
Wet/Dry Processing and Assembly of Organic, Inorganic, and Hybrid Materials and Devices
- Photolithographic-, E-beam-, FIB-Patterning/Wiring of Nanomaterials for Devices
(Through the Nanofabrication Research Laboratory) Processing of nanomaterials including spin-coating, dielectrophoretic deposition, etc. combined with photo- and e-beam lithographic techniques and FIB electrode placement for the addressing of nanomaterials as prototype devices.
- Controlled atmosphere dual glove box evaporator system for inorganic films and organic electronics
An MBraun Labmaster double glove box system with integrated vacuum deposition chamber (Angstrom Amod e-beam and thermal evaporator) and spin coater (Specialty Coating Systems Model SCS G3) is available for physical vapor deposition of metals and small-molecule organics and for spin coating of polymers in a clean, inert environment. Thermal chambers have six sources, including two RADAK sources for small-molecule deposition with co-deposition capability, which enable multilayer deposition, gradient and doping film deposition at controlled substrate temperatures (RT to 400°C). The system is also equipped for computer-controlled e-beam deposition with four pocket electron-beam sources and two thermal sources for high melting point metals and inorganic compound thin film deposition. A 400°C vacuum oven is mounted to one end of the glove box. The system has various shadow masks for patterning electrodes for various organic electronic devices including OFETs, OLEDs, OPVs, and spin valves. The system enables the assembly of organic and inorganic multilayer thin films with Ångstrom thickness resolution for organic electronic devices.
- Sonospray deposition of nanomaterials and organics
Computer-controlled sono-spray deposition of nano materials, polymers, and nano composites from solutions and suspensions for uniform or patterned deposition on small or large areas (up to 1ft x 1ft) with minimum feature size of 1.5 mm. The system enables multilayer deposition on various substrates, including polymers, while controlling the substrate temperature (up to 180C). A micro-syringe pump feeds a solution allowing deposition from small (<10ml) volumes of solution and a dual-syringe configuration allows simultaneous deposition from two different solutions with variable ratio. The system is also equipped with a sono-syringe, to prevent precipitation of material during deposition (min required volume 20ml).
- Hybrid Organic/Inorganic Perovskite Films and Device Fabrication
Formed by solution phase synthesis techniques and spin coating or Sonospray deposition. Associated layer by layer deposition, processing, and electrode application.
- 2D Crystal Stamping
A microscope based setup to transfer exfoliated or CVD-grown layers of 2D materials from polymer-coated ribbons is available, allowing the stamp-fabrication of 2D heterostructures.