Development of Measurement Setups

PID test system

PID means potential induced degradation. PID leads to a reduction of the solar cell efficiency and thus to power losses in PV systems. The PID measurement principle used in our system is based on our GRANTED ISE patents DE 102011051112 B4, CN 103874928 B, US 9506975 B1. Our unique test system offers the customer a way to test solar cell, polymer foil and glass stacks with respect to their PID sensitivity before module manufacturing. During the test a high voltage is applied to the stack at elevated temperature and the shunt resistance of the cell is measured. If PID is present, a strong decrease of the cell shunt resistance is observed.
 
Technical specifications:
  • Parallel measurement of 4 cells on one level
  • Solar cell size up to 157 mm x 157 mm
  • Thickness of sample stack: max. 10 mm
  • Temperature range: RT to 150 °C
  • High voltage: up to 3000 V
  • Dark measurement of the shunt resistance using 4-wire configuration
  • Manual loading
  • Full windows compatible user interface with easy workflow
  • Minimum measurement time 5 min, maximum time as required by the user
  • Small footprint of the basic system: 600 mm x 600 mm x 1200 mm
  • No cooling water or compressed air supply needed
  • Easy upgrade up to 8 levels (32 cells)
Fraunhofer ISE also provides measurement services for PID tests.
 
© Fraunhofer ISE

LeTID test system

LeTID (light and elevated temperature induced degradation) is a particular form of light induced degradation. LeTID leads to a reduction of the solar cell efficiency and thus to power losses in PV systems.

Our unique test system offers the customer a way to test four solar cells simultaneously with respect to their LeTID sensitivity before module manufacturing.

Fraunhofer ISE provides comprehensive measurement services for LeTID and PID.

Technical specifications:

  • Parallel measurement of 4 cells
  • Solar cell size up to 157 mm x 157 mm
  • Temperature range: RT to 150 °C
  • Degradation by current injection (standard)
  • Open circuit voltage monitoring at process temperature
  • Manual loading
  • Full windows compatible user interface with easy workflow
  • Minimum measurement time 5 min, maximum time as required by the user
  • Small footprint of the basic system: 600 mm x 600 mm x 1200 mm
  • No cooling water or compressed air supply needed
  • Full IV-curve measurement at process temperature (optional)
  • Different forward or reverse bias voltages ( - 10 V to + 0.8 V) during degradation process (optional)
  • Light induced degradation (optional)
Fraunhofer ISE also provides measurement services for LeTID tests.
 
© Fraunhofer ISE

Lab PV module laminator

The Lab PV Module Laminator is a flexible stand alone system for easy manufacturing of test modules up to 350 mm x 350 mm size. The system has a small footprint and needs only a standard power supply connection. No compressed air or nitrogen is needed for processing. The temperature ramps are free programmable, the system is operated by a programmable logic controller.

The system is ideal for universities, R&D labs or companies which want to manufacture small test modules for example for materials testing.

Technical specifications:

  • Manual handling
  • Size of heating plate: 400 mm x 400 mm
  • Maximum size of test module: 350 mm x 350 mm
  • Temperature up to 200°C
  • Free programmable heating ramps
  • Programmable logic controller
  • Vacuum pump included
  • No compressed air needed
  • Small footprint for the system: 160 cm x 80 cm

 

© Fraunhofer ISE

Shunt detection system

The Shunt Thermography is a low cost and fast system to detect shunts in solar cells. The solar cell is hold on a thermally stabilized vacuum stage. It is covered by a liquid crystal (LC) foil, that changes its color where hot spots occur. Applying a reverse voltage makes these hot spots visible that are caused by shunts. The system is a fast and easy tool do detect problems in solar cell production and helps to prevent module failures.

Typical defects which can be detected easily :

  • Edge isolation failure
  • Shunts caused by cracks
  • Shunting by metallization.

Features

  • Shunt detection within seconds
  • Solar cell size up to 156 mm
  • Durable liquid crystal foils can be easily replaced at very low cost

Included in delivery

  • Sample holder with rear contact and Peltier-cooling
  • Frame with LC foil and front contact
  • Power supply for reverse bias voltage
  • Vacuum pump
  • Peltier power supply with temperature controller
  • Spare LC foils
  • User manual

 

Shunt Messplatz
© Fraunhofer ISE

Speclab measurement setup

External quantum efficiency (EQE) measurements find widespread application for solar cell characterization. They yield depth dependent information on cell properties and quality and they enable single cell characterization in multijunction devices.
Constant photocurrent method (CPM) measurements are commonly used to determine the defect density especially in amorphous thin films.
Setups for EQE and CPM use very similar hardware components so that it is easy to combine both methods in a single measurement setup. Only a few more components and a modified measurement software are necessary to upgrade a standard EQE setup for CPM measurements.

EQE measurements setup

  • 100 W Xe arc lamp
  • Double monochromator
  • 3 gratings with 350, 750 and 1000 nm blaze wavelength
  • Stray light << 3*10-5 at 250 nm
  • 0.1 nm wavelength resolution and accuracy
  • Single beam setup for EQE measurement
  • Bias illumination with color filters for tandem cell measurements
  • Digital lock-in amplifier
  • Si reference diode
  • Measurement software with graphical user interface
  • User manual

Option 1: CPM extension

  • 100 W Halogen lamp
  • Electrometer with high sensitivity
  • 2nd digital lock-in amplifier
  • Si/InGaAS diode
  • Measurement software
  • User manual

Option 2: Contact system

  • Sample holder with contact for 36 solar cells (1 cm2) and Peltier-cooling
  • Peltier power supply with temperature controller
  • Manual switch box

 

Speclab Messplatz
© Fraunhofer ISE

Measurement block for thin film solar cells

The thin film contact system is designed for IV-curve measurements of 36 small laboratory solar cells with an area of 1 cm2 manufactured on a glass substrate. Each cell is contacted via a contact needle. The temperature of the measurement block and thus of the solar cells can be set by using a Peltierheating/cooling system. The special design of the measurement block allows a good thermal contact to the glass substrate while the cells remain isolated to each other. The cells are addressed via a switching box.

Features

  • Size of glass substrates 100 mm x 100 mm (standard)
  • 4-wire connection to each cell
  • Temperature control using Peltier cooling
  • Temperature range: 15 °C to 40 °C

Included in delivery

  • Measurement block with contacts for 36 solar cells and Peltier-cooling
  • Peltier power supply with temperature controller
  • Water Cooler
  • Manual switch box
  • User Manual

Options

  • IV-curve measurement setup
  • Automatic switch box
  • Other glass substrates on demand
  • Other contact design on demand

 

Messblock für Dünnschichtzellen
© Fraunhofer ISE

FAKIR-System

The Fakir system is a low cost and fast system to measure topograms of the sheet resistance of various samples using the four point probe technique. The sample is contacted by 400 needles at the same time. The sheet resistance at one position is measured using only four adjacent needles at a given time. The measurement position is changed just by automatically switching from one position to the next. No movements are requirded during mapping. This makes the Fakir about 10 times faster compared to conventional systems.

Features

  • Sample sizes up to 156 mm
  • Samples can be silicon wafers and films on various substrates
  • Measurement speed better than 2 points / sec.
  • Detects sheet resistances of up to 100 Ohm/sq
  • Reproducability typically within 10 %

Included in delivery

  • Main system including sample stage and contact needles
  • Switching multimeter
  • Keithley switching multimeter to precisely measure the sheet resistance
  • Vacuum pump
  • Measurement software
  • User manual

 

FAKIR-System
© Fraunhofer ISE

SigmaT Dark Conductivity measurement

Temperature dependent dark conductivity measurement σd(T) is a standard measurement technique in photovoltaic to characterize the quality for example of amorphous and microcrystalline silicon thin films. Material properties like activation energy Ea deliver information about the level of incorporated impurities. A simple coplanar contact pad structure can be used to contact the thin film to be measured. High insulation resistance of the measurement setup enables the SigmaT electrometer to record resistances up to several TΩ, which is important e.g. for measuring intrinsic amorphous silicon thin films. The heating plate’s dimensions allow substrate sizes up to 150 mm x 150 mm. By evacuating the vacuum chamber to a pre vacuum level leakage currents due to humidity are avoided. Our simple and intuitive measurement software provides full visualisation of the resistance’s temperature dependence and can generate reports including the results in charts and graphs.

Features

  • Vacuum chamber with pmin < 3.0 ∙ 10 -2 mbar
  • Heating plate with Tmax of 473 K
  • Heat up time < 10 min to reach 433 K
  • Substrate sizes up to 150 mm x 150 mm
  • Maximum measurable resistance 200 TΩ

Included in delivery

  • Vaccum chamber
  • Vaccum pump
  • Vaccum controlller
  • Heating plate
  • Temperature controller
  • Electrometer
  • PC
  • Measurement software
  • Manual
SigmaT Messplatz zur Bestimmung von Dunkelleitfähigkeiten
© Fraunhofer ISE