The current-voltage (IV) characteristic of a solar cell is an essential performance metric. While flash tester solutions provide the necessary data for cell binning in production environments, steady-state illumination measurements provide a greater range of possibilities. The flexibility to conduct measurements under in wide ranges tunable illumination, electrical and temperature conditions is the key to state-of-the-art measurement and analysis methods. neonsee‘s highly integrated turn-key IV test solutions offer full control of these parameters, all programmable by intuitive software, facilitating comprehensive IV derived loss analysis of solar cells.
Measurement capabilitiesSteady-state solar simulationMulti-zone spectrum tuningBeam divergenceAutomated sample loadingBifacial
illuminationTechnical featuresGeneralReferences
illuminationTechnical featuresGeneralReferences
Measurement capabilities
| Methods | Results |
|---|---|
| llluminated IV | Isc , Voc , lmpp , Vmpp , FF, efficiency, Pmax , Rs , Rsh |
| Dark IV | Rsh |
| Isc-Voc / Suns -Voc | Leff , Rs-free IV characteristics, pFF, FF0 , Rs from FF & pFF |
| Variable intensity / weak light | Isc(E), Voc(E), lmpp(E), Vmpp(E), FF(E), efficiency (E), Pmax(E), Rs(E), Rsh(E) |
| EL / PL | Rs distribution, cracks, contact quality, etc. |
| Breakdown characteristics | Breakdown voltage Vbd , 1@ programmable voltages |
| Temperature coefficients | a (lsc) , ß (Voc) , y (Pmax) |
| Light soaking | Long term analysis under different operating conditions: Isc , Voc , Vset , MPP tracking |
| Voc method | Voc (t) reveals accurate Voc at a known junction temperatured |
| Hysteresis measurement | Capacitance indication / FF eviation |
| Diode model fitting | Diode saturation currents 101 & 102 , ldeality factors n1 & n2 |
| Rs analysis | Double-light method (IEC 60891), comparison of Isc-Voc & illuminated IV or dark IV & illuminated IV |
| Spectrum | Spectral distribution, mismatch factor, IEC 60904-9 & ASTM E 927 classification |
Technical features
Sample holder for bifacial solar cells
- Exchangeable cover plates with different reflectance properties 3-6 busbar designs
- Adjustable contact bar distance
- Integrated temperature sensing
- Contact bar features like “Ultra-Thin Contact Bars” (see above)
Micromanipulators
- Adjustable contact pressure
- Various probe tip diameters & shapes available
- Magnetic base for easy positioning
- Adjustable probe tip holder extension
Sample temerature control
- Liquid-based and thermoelectric temperature control options
- 10 – 80°C standard temperature range: Extended temperature ranges on request
- Closed loop feedback control of sample temperature
- Spring loaded temperature sensor integrated in sample holders
- Programmable temperature scans
Data Acquisition
- 4-Quadrant electronic load/source
- 16 Bit FPGA-based data acquisition
- Current measurement resolution 0,3nA
- Voltage measurement resolution 300µV
- Simultaneous measurement of current, voltage, irradiance & temperature
- Acquisition of entire IV curve in less then 2ms
- Programmable voltage sweep
Software
- Recipe-based configuration
- Perform complex measurement sequences with ease
- Report generation
- Database connectivity
- Additional features upon customer request
Contacting systems
- True 4-point probing
- Customized solutions for silicon, thin-film, organic & multi-junction solar cells
- Multiplexers for automated measurement of multi-cell samples
- Integrated temperature sensing
- Vacuum sample fixing
Ultra-thin contact bars for 5/6 solar cells
- Contacting of busbars with width < 0,5mm
- 1 mm contact bar width
- 15 IN probe tip pairs in 10mm distance 0,3mm diameter probe tip with crone head
- Stretching mechanism to avoid bending of bar
Contacting system for multi-cell samples
- 4-point probing of all solar cells
- Available for superstrate and substrate configurations
- Adjustable contact point distances
- Integrated temperature sensing
- Automated measurement sequences with 24 – 96 channel IN multiplexer
For more information on Solar Cell Analysis, please contact us:
