Photovoltaic spectrometer for solar cells characterization

Description

Photovoltaic Spectrometer 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 provides wavelengths range that covers UV, VIS and IR light. Furthermore, the sample may be excited 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.

Spectrometer modules

Sample Chamber interior

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),
Filter Wheel
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.

Potentiostat

Bias potential range: -5 V ÷ 5 V,
Current ranges: 100 nA, 1 µA, 10 µA, 100 µA, 1 mA, 10 mA, 100 mA,
Current resolution: from 1 pA to 100 nA (range dependent),
Controller
Maximum sampling rate: 1 kSample/s,
Connection with PC: via USB 2.0,
Two photodiodes inputs handled simultaneously (Monitor Photodiode and Integrating Sphere photodiode/transmitted light photodiode),
RS485 socket to control devices,
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.

Experiment results examples

Photocurrent measured for the standard crystalline silicon solar cell as a function of the incident wavelength.

External Quantum Efficiency evaluated for the perovskite solar cell.