Lab Facilities

Students in the Xu Group will learn various cutting‐edge techniques available on campus or through the existing collaboration with Argonne National Laboratory, including scanning probe microscope, scanning electron microscope, transmission electron microscope, high vacuum deposition system, quartz crystal microbalance, electrochemical potentiostat and other electronic instruments.

• Solar Simulator and Potentiostat
• Potentiostat/Galvanostat/Zero Resistance Ammetry (ZRA) (Garmy Reference 600)
• Computerized Battery Analyzer
• Jandel Multiheight Four‐Point Sheet Resistance Measurement System
• Gravimetric Sorption Analyzer
• Nanogravimetric Hydrogen Storage Measurement System
• Scanning Electron Microscope
• Scanning Probe Microscope
• Isothermal Electrochemical Synthesis Facility
• High Vacuum Coating System
• Thermal Gravimetric Analyzer
• Ozone Generator
• Quartz Tube Furnace
• SPEX 8000M Mixer/Mill
• QEXL Solar Cell Quantum Efficiency Measurement System
• UV–Vis–NIR Thin Film Reflectance Spectrometer
• Temperature Controlled Vacuum Oven

Solar Simulator and Potentiostat

A Class B solar simulator (Photo Emission Tech.) and a potentiostat (Gamry Reference 600) for I–V and impedance measurement.

Potentiostat/Galvanostat/Zero Resistance Ammetry (ZRA) (Garmy Reference 600)

A Potentiostat/Galvanostat/Zero Resistance Ammetry (ZRA) (Garmy Reference 600) is used for all types of physical electrochemistry (PEC) measurements and electrochemical impedance spectroscopic (EIS) of electrochemical devices such as solar cells, Li‐ion battery and fuel cells.

The PEC study includes chronoamperometry, chronocoulometry, chronopotentiometry, controlled potential coulometry, cyclic voltammetry, linear sweep voltammetry etc. and the EIS study includes Galvanostatic EIS, hybrid EIS, Mott Schottky measurement, multiplexed potentiostatic EIS, potentiostatic EIS, single Frequency EIS, etc.

Computerized Battery Analyzer

Two Computerized 8‐Channel Battery Analyzers (0.002~1mA and 0.1–10 mA, all up to 5V) for R&D Battery Electrodes Analysis. A coin cell assembling system enclosed in the Ar glovebox.

BTS8‐MA is an eight‐channel battery test system for R&D all types rechargeable batteries at 0.002~1mA and 0.1–10mA up to 5V. This system provides most applications in battery testing fields such as electrode materials research, battery performance test including lifetime cycling, small‐scale battery formation, capability grading, battery pack testing etc.

Jandel Multiheight Four‐Point Sheet Resistance Measurement System

This system is composed of a four point probe head, operating lever and micro‐switch. The probe head is connected to the portable Jandel HM 21 meter which supplies a constant DC current and displays the measured output voltage. This system can measure resistivity of bulk samples between 0.01Ω. cm to 100KΩ.cm and sheet resistance for thin film samples from 0.01Ω/square to 10MegaΩ/square.

Gravimetric Sorption Analyzer

Image and schematic diagram of a homemade gravimetric gas sorption measurement system. The core of the gravimetric sorption analyzer is a highly sensitive electromagnetic beam microbalance (C.I Electronics, UK) that can be operated in pressure up to 100 bar. The balance head (Model MK2) is enclosed in a non‐magnetic steel chamber and connected to a high‐pressure 8‐wire NPT feedthrough (Conax Technology Inc. NY), through which the balance head is connected with a control unit for input/output to a computer. The ultimate weight readability can reach 0.1 ug. The sample is placed in a brass cup (416 mg) hung on one side of the beam, while the counterweight is hung on the other side of the beam. The electric adjustable range of the balance head is ±500mg. With a VCR fitting (Swagelok) at the hang down port, the sample side is sheathed in a non‐magnetic steel tube for convenient sample loading. In addition, an isothermal jacket is welded to the middle section of the steel tube for flow of coolant exactly at room temperature, thus a steady temperature distribution along the testing tube can be established and the region above the cooling jacket maintains at room temperature. A metal block heater (Ucal) is used for heating.

Nanogravimetric Hydrogen Storage Measurement System

Diagram and images for a homemade nanogravimetric hydrogen storage measurement system based on a quartz crystal microbalance (Maxtek Inc.). The pressure cell and all samples are enclosed in an ultrapure Ar glovebox (O₂<0.5ppm). For mechanism of the QCM‐based nanogravimetric gas sorption system, please refer to our publications.

Scanning Electron Microscope

A high‐vacuum tungsten filament Scanning Electron Microscope (Tescan, model Vega II SBH) equipped with an liquid nitrogen‐free INCAx‐act Analytical Standard EDS Detector (Oxford Instruments).

Scanning Probe Microscope

An Agilent 5400 Scanning Probe Microscope.

Isothermal Electrochemical Synthesis Facility

A home‐assembled isothermal electrochemical synthesis facility including a computer‐controlled pulse electrochemical deposition system and an electropolishing and anodization system for preparation of various nano‐architectured materials for solar cells, Li‐ion battery and supercapacitor applications.

High Vacuum Coating System

High vacuum coating system (Edward Auto 306) with two thermal evaporation sources and one customer‐installed HV sputter source.

Thermal Gravimetric Analyzer

A thermal gravimetric analyzer (Perkin–Elmer, model Pyris1) system enclosed in an ultrapure Ar (O₂<0.5ppm) glove box.

Quartz Tube Furnace

A computer controlled quartz tube furnace with gas flow control system used for reactions that require high temperature up to 1300 oC and CVD applications.

SPEX 8000M Mixer/Mill

SPEX 8000M Mixer/Mill is a laboratory scale, high‐energy ball mills, which grinds samples by placing them in a container along with one or more grinding elements and imparting motion to the container. It is designed to pulverize a sample rapidly while mixing it homogeneously: an approach long known to be effective in preparing samples for emission spectroscopy and XRF spectrometry. It is also widely used for blending powders and making emulsions. Due to its high‐energy action the SPEX SamplePrep 8000M Mixer/Mill in particular has recently become indispensable in the search for superconducting alloys.

QEXL Solar Cell Quantum Efficiency Measurement System

A QEXL Solar Cell Quantum Efficiency Measurement System (PV Measurement) with 300 nm to 1100 nm scan range high resolution scan in under 1 minute and probe beam from 1 mm to 20 mm. Seamless switching between DC and AC measurement modes, 1 Hz to 120 Hz chopping frequency.

UV–Vis–NIR Thin Film Reflectance Spectrometer

A UV–Vis–NIR thin film reflectance spectrometer (Filmetrics F20–EXR thin‐film analyzer) with an integrating sphere.

Temperature Controlled Vacuum Oven