Focus: Solar Fuels, Photovoltaics
Lab PI: Nicolas Gaillard
The research team at the Thin Films Laboratory is developing unique materials and interfaces for 4 key applications:
Tunable semiconductors for renewable hydrogen production (solar fuels),
“Printable” solar absorbers for advanced/low-cost photovoltaics,
Transparent Conductive Flexible Composites for In-Mold Electronics, and
Quantum dots/nanoparticles for photocatalysis and water remediation.
For over two decades, the Thin Films Laboratory (TFL) at the Hawaii Natural Energy Institute (HNEI) has been a leader in innovative material research and development for solar energy converter systems. Specifically, the TFL groundbreaking approach in material R&D allowed for a better understanding of the fundamental properties of numerous photovoltaic technologies, including amorphous silicon and polycrystalline copper-indium-gallium-diselenide (CIGSe) alloys. Aside from “conventional” PV systems, HNEI-TFL research activity also comprises the discovery of new photo-catalytic materials capable of direct conversion of sunlight into usable chemical energy, a.k.a. “Solar Fuels”, with focus on solar-driven water splitting for hydrogen production.
The Thin Films Lab is a unique facility at HNEI, situated with sophisticated state-of-the-art equipment for the fabrication of thin film materials and devices, including co-evaporation chambers, sputtering systems and plasma enhanced chemical vapor deposition devices.
Vacuum Deposition Chambers
- CIGS Evaporation System: Varian 3125 diffusion-pumped multisource evaporator including five independently-controlled furnaces for elemental co-deposition of copper, indium, gallium, selenium and sodium. For fabrication of CuInSe2, Cu(In,Ga)Se2 and CuGaSe2 photovoltaic materials and devices.
- Sputtering Deposition System: Perkin-Elmer 2400 cryo-pumped three-gun co-sputtering system. Can accommodate both 2” and 3” sputtering targets. Applications include: transparent conducting oxides; catalysts and other novel films.
- Metal Thermal Evaporation System: NRC 3117 diffusion-pumped four-source thermal evaporator for depositing anti-reflective coatings, metallic films and contact grids.
- Glove Box: Inert 2G glove box for storage and processing of air-sensitive chemicals. Moisture and oxygen levels controlled down to 0.5ppm and 2 ppm, respectively.
- CdS Film Deposition: chemical bath system for heterogeneous deposition of various buffer materials, including CdS, In2S3 and Zn(O,S). Spin Coaters: commercial (in air) and custom (in glove box) spin coaters for molecular ink processing. Coaters can accommodate samples up to 3” in diameter.
- Furnaces: custom tube and vacuum furnaces for sample thermal treatment. Furnaces can be used to treat samples under oxygen, sulfur or selenium environment at temperatures up to 600 °C.
- Semiconductor/Solar Cell Characterization Stations: including high-precision electronic measurement equipment, temperature-controlled probe chuck (down to 50K), solar simulator (1,000W Xe) and LED light sources. Measurement capabilities include:
- temperature-dependent light/dark JV characterization (pA resolution)
- temperature-dependent AC & DC conductivity measurement
- temperature-dependent CV measurement
- Electrochemical Test Station: including high-precision electronic measurement equipment and Plexiglas or glass fixtures for test- and reference-electrode mounting. Measurement capabilities include voltammetry and cyclic voltammetry (pA resolution), and long-term corrosion testing.
- Quantum Efficiency System: PVMeas QE7 for measurement of photocollection in thin film devices in the 300 – 1200nm wavelength range.
- UV-VIS Photospectrometer: Perkin-Elmer model Lambda 750 with integrating sphere: for optical transmission, reflection and absorption measurements of thin films in the 250- 2,500 nm range.
- Surface Profilometer: Tencor D-500 for thin-film thickness measurements.
- Four-Point Probe Station: Signatone model S301-6: automated system for film resistivity measurements.
Advanced analytical methods at the University of Hawaii at Manoa
In addition to the HNEI equipment listed above, the UH campus boasts a wide range of sophisticated surface analysis techniques which are generally available on a recharge basis:
- Advanced Confocal Microscope (Bio-Rad Micro-science Division)
- Atomic Force Microscope (Nanoscope Instruments)
- Scanning Tunneling Microscope (Nanoscope Instruments)
- Scanning electron microscopes (FEI Helios NanoLab 660 Extreme High Resolution Dual Beam FIB)
- Transmission electron microscopes (FEI Titan 300 keV)
- X-ray diffractometers (Bruker D8 Advance and D8 Venture)