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 sun light 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.

The research team at TFL is also actively participating in the development of new low-cost synthesis protocols as a substitution to high temperature/vacuum based thin films deposition techniques. The recent introduction of chemistry in solar cell manufacturing was undoubtedly a game changer in material design and could potentially reduce cells production cost. After two decades of R&D in vacuum-based thin film material synthesis, HNEI TFL is now taking a step further toward chemical-based solar cell manufacturing.

For further information about this facility and the research activities carried out in it, contact Nicolas Gaillard [1].

Deposition Equipment

	PECVD System [2]: MV-Systems dual-chamber high-vacuum "plasma enhanced chemical vapor deposition" system with load lock for depositing amorphous and microcrystalline silicon and germanium alloys. Applications include fabrication of photovoltaic materials and devices; and visible and infrared sensors.
	CIGS Evaporation System [3]: 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 CIS and CIGS photovoltaic materials and devices.
	Sputtering Deposition System [4]: Perkin-Elmer 2400 turbomolecular-pumped three-gun co-sputtering system. Applications include: transparent conducting oxides; catalysts and other novel films; and refractory metal films.
	Metal Thermal Evaporation System [5]: NRC 3117 diffusion-pumped four-source thermal evaporator for depositing metallic films and contact grids.
	Diamond-like Films: ASTEX PDS-16 microwave plasma enhanced diamond deposition system. Not currently operational.
	CdS Film Deposition: Chemical bath system currently handling two 5 cm x 9 cm substrates. Expandable to a larger area.

Instrumentation

	Semiconductor/Solar Cell Characterization Station [6]: including high-precision electronic measurement equipment, temperature-controlled probe chuck, solar simulator 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 transient response characterizations (ns resolution)
	Electrochemical Test Station [7]: including high-precision electronic measurement equipment and Plexiglas fixtures for test- and reference-electrode mounting. Measurement capabilities include voltammetry and cyclic voltammetry (pA resolution), and long-term corrosion testing.
	Quantum Efficiency System [8]: MRG model QE1800 for measurement of photocollection in thin film devices in the 350 - 1800nm wavelength range.
	UV-VIS Photospectrometer [9]: Perkin-Elmer model Lambda 2 with integrating sphere: for optical transmission, reflection and absorption measurements of thin films.
	Surface Profilometer [10]: Tencor Alpha Step model 200 for thin-film thickness measurements.
	Four-Point Probe Station [11]: Signatone model S301-6: automated system for film resistivity measurements.
	Gas Chromatograph: Varian with TCD/FID detectors. Gas Chromatograph: Shimadzu GC14-A.

Surface Analysis at UH
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.

X-ray Diffraction system (Scintag model PAD V) Scanning Electron Microscope (Zeiss Model DSM-962) with EDX capability High resolution Scanning Electron Microscope (Hitachi model S-800) Fourier Transform Infrared Spectrometer (Thermo-Nicolet) Two Spex triplemate Raman instruments with C.C.D. detectors, computer controlled data acquisition system and micro Raman attachment Advanced Confocal Microscope (Bio-Rad Micro-science Division) Atomic Force Microscope (Nanoscope Instuments) Scanning Tunneling Microscope (Nanoscope Instruments) Ernst-Leitz Scanning Acoustic Microscope (ELSAM) Sandercock six-pass tandem Brillouin scattering system Fully automated ellipsometer (Auto-EL-III Rudolph Research)