GIANTFab - Instrumentation

The GIANTFab core facility provides a set of equipment for fabricating and testing thin-film optical, optoelectronic, and electronic devices inside of series of linked nitrogen-atmosphere gloveboxes.

The fabrication equipment includes:

• Sonicator
• UV/Ozone cleaner
• Benchtop spincoater (NiLo Scientific)
• Two inert-atmosphere spincoaters (Specialty Coating Systems)
• Vacuum oven (LCTech)
• Precision hotplate (Wenesco)
• Metal evaporator (LCTech)
• Organic evaporator (LCTech)

The testing equipment includes:

• Keithley 2400 with various probe stations
• Custom sample holders for various electrode configurations
• Light-tight inert atmosphere sample box
• Solar simulator
• Monochromatic light source with chopper and lock-in amplifier
• J-V testing
• EQE testing
• Conductance testing and other electrical tests

The spin-coaters and vacuum depositors are suitable for a range of uses. The testing equipment is can be used for any measurement the Keithley 2400 can perform, including J-V curves, conductance measurements, and power measurements for EQE testing. Existing software is optimized for organic, perovskite, and hybrid organic-perovskite solar cells.

All instrumentation and services are available to researchers at Northwestern and other universities as well as industrial researchers. If you have any questions or comments about the core’s capabilities, are interested in using the lab's equipment, or would like more details about rates, please contact the GIANTFab Operations Director Nathan La Porte.

Access to the core facility is limited to users who have been trained on the equipment. To request training or to reserve the equipment, please visit our NUcore page.

All the services below are contained within a set of nitrogen-filled gloveboxes that maintain an atmosphere of <1 ppm O₂ and H₂O. The spincoaters are housed within one glovebox, the evaporators in a second, and the testing equipment in a third. Each glovebox is accessible from the outside through an antechamber, and materials can also be transferred between boxes without removing them from the nitrogen atmosphere. Access to the systems and billing for usage is managed through NUcore.

For users interested in performing Atomic Layer Deposition (ALD) on devices fabricated in GIANTFab, we have partnered with REACT, the Reactor Engineering and Catalyst Core Testing Facility, to offer inert-atmosphere transfer in and out of their ALD apparatus. For more information, please contact both the GIANTFab and REACT staff. 

Substrate Preparation

Branson M1800H Ultrasonic Cleaner

For cleaning of substrates, we have a heated ultrasonic cleaning bath with plastic beakers that hold our substrate boats. The sonicator is free to use. 

UV/Ozone Cleaner

There is a UV/Ozone substrate cleaner located inside the spincoater glovebox. It is free to use as well. 

Spin Coaters

NiLo Scientific Spincoater 5

NiLo Spincoater: Manual

This spincoater is located on the benchtop. It can be used for deposition of soluble thin films that are not air-sensitive, such as PEDOT:PSS layers for thin-film photovoltaics. It can accommodate substrates up to 5 inches in diameter.

Aqueous solutions can be spincoated on the benchtop in the GIANTFab laboratory. For solutions containing volatile or hazardous solvents, the spincoater can also be rented on a daily basis for use in your own lab fume hood. 

Specialty Coating Systems G3P8 Spincoater

Spincoater: Standard Operating Procedures

The spincoater glovebox has two Specialty Coating Systems G3P8 spincoaters integrated into it. Each spincoater is contained in a well flush to the floor of the glovebox. Users provide their own substrates and active layer solutions and are charged by the minute with a minimum reservation of half an hour. The spincoaters are equipped with a 3/8 inch diameter chuck. Users are welcome to purchase and use a different size chuck by arrangement with GIANTFab staff. 

Common solvents used for preparation of active layer solutions are available for purchase, and users may store their purchased solvents in the box.

The spincoater box has a UV/ozone substrate cleaner for substrate preparation and a balance and hot plate stirrer for active layer solution preparation. These can be used when the spincoater is reserved at no additional charge.

For annealing of substrates after spincoating, the box also contains a Wenesco HP66U hotplate and LCTech vacuum oven. Each of these can be reserved separately for thermal or solvent vapor annealing.

Vacuum Deposition Systems

Vacuum Deposition: STANDARD OPERATING PROCEDURES 

The evaporator glovebox has two separate vacuum evaporators that can be used independently. Each evaporator consists of a cube-shaped stainless steel chamber approximately 20 inches (500 mm) on a side, with a sliding front door with a view port and a swing-out rear door. The chamber is evacuated using a turbomolecular pump backed by a dry scroll pump to achieve a base pressure of 1 × 10–6 mbar.

Substrate holders are available for common sizes of substrate. Masks for patterned deposition are available in several pre-made configurations, and GIANTFab staff can assist in the design and fabrication of custom deposition masks.

In addition, we have an adjustable substrate holder for large or odd-sized substrates.

Consult with GIANTFab staff for details.

Each vacuum depositor has a quartz crystal deposition thickness monitor. Deposition can be controlled manually or automatically using an Inficon deposition controller. 

Metal Vacuum Deposition System (LC Technology DS-110 Vacuum Deposition System)

The metal evaporator has four thermal sources with 2 KW power supplies. Each source can be individually controlled and is equipped with a pneumatically controlled shutter. The stage can be cooled to –10 °C, and is protected by a pneumatically controlled source shutter.

GIANTFab has a standard mask that produces six 6.0 mm² devices and is compatible with the custom cell holder in our testing system. Users are also welcome to supply their own masks. ITO-on-glass substrates for this mask are available for purchase.

It is charged by the minute with a minimum reservation of one hour. This depositor is suitable for metals such as silver, aluminum, and gold as well as inorganic compounds such as molybdenum oxide and lithium fluoride.

Common metals and tungsten evaporation boats are available for purchase by users, and users can store their purchased metals and boats in the box. 

Organic Vacuum Deposition System (LC Technology DS-110 Vacuum Deposition System)

The organic evaporator has four organic sources, two with 10 mL capacity (Kurt J Lesker LTE 10) and two with 1 mL capacity (Kurt J Lesker LTE 1). All have a temperature range of 50–600 °C. Each source can be individually controlled and is equipped with a pneumatically controlled shutter. The stage can be heated up to 200 °C, and is protected by a pneumatically controlled source shutter. It is charged by the minute with a minimum reservation of one hour. Ceramic crucibles for the organic evaporator are available for purchase, and users may store their purchased crucibles in the box. 

This depositor is suitable for deposition of organic and organometallic materials such as C₆₀, organic dye molecules, other organic layers, and metalorganic compounds like phthalocyanines and porphyrins. 

Electronic Testing

Keithley 2400 Source Measurement Unit with probe station and sample holders

The testing glovebox is equipped with a Keithley 2400 Source Measurement Unit (SMU). Using the four banana jack passthroughs, the SMU can be connected to an adjustable four-point probe station, or to a number of different substrate holders that match the various electrode and device masks available on the depositors.

In addition to the banana jacks, the glovebox also has two BNC passthroughs and a USB passthrough, to allow additional testing equipment to be installed inside the glovebox. Please consult with the facility staff to discuss how we can accommodate your testing requirements.

The testing station is also interfaced with a PV testing system, as described below: 

Sciencetech PTS-2 Quantum Efficiency/IPCE Measurement System

The Sciencetech PTS-2 is an integrated system for performing J-V and EQE testing on solar cells. Light is provided through fibers from the class AAA solar simulator and monochromated light sources. Front or rear illumination is possible, and custom substrate holders can be easily connected in addition to the standard four-point probe setups. It is charged by the minute, with software and data analysis training in the usage fee.

The solar simulator can be attenuated using a set of integrated filters to test photocurrent response under varying levels of illumination. 

Storage in glovebox

Each glovebox contains a number of plastic bins for medium-to-long term storage of materials in an inert environment. Users may rent storage space on a monthly basis to make use of these bins. Materials found inside the glovebox not stored in bins will be discarded.

Rates and Access Hours

Hourly instrument rates for FY2021 are as follows. Note that the current members of the Chicago Biomedical Consortium, whose students and staff are entitled to the internal academic rate, are Northwestern, University of Chicago, and University of Illinois at Chicago. All other academic users pay the external academic rate.

GIANTFab is open to all users at all times to accommodate shifted lab schedules during the COVID-19 pandemic. The annealing equipment can be reserved overnight on weekdays by all users at a 50% discount.

Superusers are permitted 24/7 access to all equipment. If you are interested in becoming a superuser, please contact GIANTFab staff.