Quantum Efficiency Measurement Station: Automated, comprehensive tool for solar cells characterization, measuring quantum efficiency and key performance parameters.
Description
Quantum Efficiency Measurement Station
The Quantum Efficiency Measurement Station is a complete experimental setup for solar cells spectral response investigation. The sample is illuminated with a monochromatic beam produced by the Monochromator with two types of light sources at the entrance: Xenon Lamp and Halogen Lamp. Both lamps provide wavelengths range that covers UV, VIS, and IR light. Instrument with the BIAS Light extension enables to excite the sample with a normalized white AM1.5G light from an additional Xenon Lamp combined with the Air Mass Filter. The examined cell is placed on a motorized vacuum XY Table, with a manual Z shift.
Measurements are performed in a chamber that screens the setup from ambient light and external EM fields. The incident light intensity is monitored with a Dual Band Si/InGaAs Photodiode. All the system components are fully automated, controlled via software.
⬛ Quantities measured by the instrument:
- I-V characteristics
- Open Circuit Potential (OCP) under illumination
- Spectral reflection coefficient (R)
- Spectral transmission coefficient (T)
⬛ Characteristics:
- External quantum efficiency (EQE or IPCE)
- Internal quantum efficiency (IQE or APCE)
- Short-circuit current density (Jsc)
- Fill Factor
QE Measurement Station modules
⬛ The system consists of:
- Sample Chamber
- Motorized Multi-Axis Vacuum Table with a built-in photodiode
- Integrating Sphere
- Monochromator with two entrance slits for automatic switching between light sources
- Xenon Lamp at the first entrance of the Monochromator
- Halogen Lamp at the second entrance of the Monochromator
- Lock-in for measured signals processing
- Xenon Lamp + AM1.5G Filter (BIAS Light extension)
⬛ Sample Chamber interior
⬛ Photocurrent measurement / Reflected flux measurement / Built-in photodiode for Transmitted flux measurement
Specifications
*Instrument performance may be tailored to the certain requirements
⬛ General
- Total wavelengths range: 200 ÷ 1650 nm
- Adjustable white light beam intensity on the sample: 0.01 ÷ 0.1 W/cm²
- Illumination homogeneity: 10%
⬛ Xenon Lamp
- 150 W xenon burner
- Water cooling system
- Low EM emission igniter
- Stabilization modes:
– electric current stabilization (distortions < 1%)
– electric power stabilization
– light intensity stabilization (unique solution to provide constant sample illumination during the experiment) - Maximum radiation intensity on the sample: 35 mW/cm²
⬛ Halogen Lamp
- Electrical power of halogen bulb: 150 W
- Reflector type: elliptic
- Air cooling system
⬛ Monochromator
- Three gratings on the turret, each optimized for different wavelengths range
- Automated grating switching depending on the wavelength selection
- Motorized output and input slits, controlled via software
- Two input slits for different light sources, switched via software
- Entrance and output slit opening range: 0 ÷ 5 mm
- Motorized internal shutter, that provides full cut off of the light beam
- Maximal spectral resolution: 0.1 nm (depends on the input and output slits width)
- Chopper at the output
⬛ Filter Changer
- Placed at the Sample Chamber entrance
- Up to 6 filters
- Two edge (long pass) filters provided by default: 400 nm and 600 nm
⬛ Detectors
Dual Band Si/InGaAs Photodiodes are used to monitor the incident light intensity, the flux transmitted through the sample, and the flux reflected by the sample
⬛ Lockin
- Bias potential range: -5 V ÷ 5 V
- Current ranges: 1 µA, 10 µA, 100 µA, 1 mA, 10 mA, 100 mA
- Current resolution: from 1 pA to 100 nA (range dependent)
- Maximum sampling rate: 1 kSample/s
- Connection with PC: via USB 2.0
- Two photodiodes inputs handled simultaneously (Reference Photodiode and Reflectance/Transmittance Photodiode)
- DC and AC measurement mode
- Input gain: x1, x2, x4, x8, x12
- Integration time: 1 ms ÷ 10 s
⬛ Motorized Multi-Axis Vacuum Table
- Maximum sample dimensions: 20 x 20 cm
- Contact electrodes placed manually at any point of the sample
- Golden coating
- Movement range for Z axis: 12 mm (manual)
- Movement precision: 0.01 mm
- Built-in detector for transmitted light detection
- Adjustable contact pins for photocurrent measurements
- Vacuum pump integrated to keep the sample in stable position
