Facilities

VersaLab™, 3 Tesla, Cryogen-free Physical Property Measurement System, 50K-400K

  Thermoelectric and Thermomagnetic bulk measurements

•     Electrical conductivity,
•     Seebeck coefficient
•     Thermal conductivity
•     Hall data
•     Nernst coefficient
•     Heat Capacity

Electrical Transport Measurement (thin films and 2D materials)

The closed-cycle cryogen-free cryostat with a temperature range from 10 K – 800 K provided by Janis Research Co.,  is our base setup for organic and inorganic thin-film TE material measurements.

We are designing stages for thermal conductivity, electrical conductivity, Hall mobility, Seebeck coefficient, and Nernst coefficient measurements of different samples to be used inside the cryostat. Lake Shore temperature controller is used for scanning the targetted temperature range.

A helium compressor is used to lower the temperature along with cold finger extension.

Thermo-reflectance Measurements

Micro-Sanj thermal imaging setup is capable of providing a 2D temperature map of devices under bias with a temperature resolution of 0.1K. It is a powerful tool for device failure analysis, thermal management in devices, and studying heat transport in transient and steady states. 

Low Vibration Cryostat for Termo-reflectance, Optical, and electrical measurements

Our cryostat, custom-made by Advanced Research System, Inc., can work in the temperature range of 10 K – 800 K. The packaged sample will be placed in a small chamber with an optical window on top. The addition of the optical window enables the usage of the thermal imaging system from Microsanj and we can obtain temperature maps or heating/cooling curves of devices at different ambient temperatures under various biases. Other electrical measurements can also be conducted using this setup.

LFA 467 Flash Diffusivity Instrument

  Allows bulk sample thermal diffusivity measurement in the temperature range of -100°C to 500°C. The instrument can be used for samples with thermal diffusivity in the range of 0.01 mm2/s to 1000 mm2/s. In carrying out a measurement, the lower surface of a plane parallel sample is first heated by a short energy pulse. The resulting temperature change on the upper surface of the sample is then measured with an infrared detector. Thermal diffusivity is then extracted from the change of upper surface temperature with respect to time.

Wire Bond System

  The wire bond system from Micro Point Pro Ltd. is used to make electrical connections between the sample and the dual in-line package. The packaged sample can then be mounted onto the cryostat for measurements. The machine has both semi-automatic and manual modes with a Z option. The bond wires that we currently use are made of gold or aluminum. 

The Cary 5000 is a high-performance UV-Vis and NIR spectrophotometer with superb photometric performance in the 175–3300 nm range. Using a PbSmart detector, the Cary 5000 extends its NIR range to 3300 nm making it a powerful tool for materials science research. It is used for transmission, reflection, and absorption measurements.

High Energy and Low Energy Ball-mill

The VQ-N High Energy Vibratory Ball Mill is capable of wet and dry grinding as well as mixing a variety of solids, suspended liquids, and pastes. It can work at 1200 rpm continuously for 9999s. The powders in the sealed jar are ground by the stainless-steel grinding balls and the inner wall intensively to make mechanical alloying happen.

Low energy: Planetary Ball Mill setup, 4x100ml Gear-Drive 0.4L

Hot press OTF-1700X-RHP4 is a Vacuum Rapid Heated Pressing Furnace (VRHP or RHP) designed for sintering powders into dense pallets under vacuum or the protective gas environment. It is capable of pressing the materials in the graphite die under 54Mpa pressure while being heated up to 1700 ºC

Chemical Vapor deposition (CVD): 1500°C Max Dual Zone Sliding Tube Furnace (50mmOD)w/Flg for Fast Heating/Cooling-OTF-1500X-II-50SL

Tube Furnace and Gas Mixing System. The 1 Zone 1200°C Tube Furnace and the 4 Channel Gas Mixing System from Across International provide the capabilities of chemical vapor deposition (CVD) and high-temperature annealing.

Box Furnace: 1100°C Compact Muffle Furnace (4x4x4",1.0L) with Programmable Controller, 110V - KSL-1100X-S-LD

This home-built 2D material transfer system combines the imaging module from Olympus and the manual stages from Thorlabs. It can be used to transfer exfoliated 2D flakes to desired locations on a substrate and also to pick up and stack flakes to build heterostructures. The bottom stage is rotational, which makes it possible to fabricate twisted layers.

Vacuum chamber with water cooling, provided by Kurt J. Lesker. We build sample stages incorporated inside the vacuum chamber to characterize high-temperature thermopower,  electrical resistivity, and thermal conductivity of bulk thermoelectric materials.

The Van der Pauw method is used commonly for the electrical resistivity of small-size wafers and thin film materials. This setup is now installed in our laboratory and is calibrated by measuring the electrical resistivity of Nickel 270(with an error of less than 1.4%).  

Keithley power supply and voltmeters are used to send current and measure voltage. The setup is controlled by a Labview program.

• Fume Hood
• GloveBox
• Spin Coater
• Microscopes
•