In the solar industry, there are diverse measurement requirements which range from solar simulator characterization and direct solar measurements to solar simulator characterization and process control applications in the production of thin film photo-voltaic panels.
Avantes has worked closely with several research and industrial clients in the solar industry to design spectroradiometry and spectroscopy instruments which fulfill the needs of this rapidly growing industry.
Monitoring/Quality Control in Thin Film Production
During the manufacture of thin film solar panels, a process control called inline monitoring is performed. This process control needs high speed and continuous spectral data acquisition over extensive production runs.
Standard applications involve reflection measurements or real-time plasma emission monitoring from 200 to 1700nm range during the deposition process of CdTe and CIGS materials on substrate materials. It is often desirable to have multi- point monitoring in different stages of the process and at frequent intervals across a web of material.
Figure 1. Multichannel AvaSpec spectrometer
Avantes’ multichannel AvaSpec spectrometer (Figure 1) is suitable for inline spectroscopic measurements. These instruments can support up to 10 concurrently spectrometer channels; the rack-mount platform is designed to accommodate several detector options ranging from front-illuminated CCDs to back-thinned CCDs for the NIR.
By means of a high speed USB2, communication is realized with the host computer and the analog and digital input/output capabilities of the Avantes AS5216 allow for excellent interface with other devices. The AvaSpec- NIR256-1.7, AvaSpec-2048L-USB2, and AvaSpec-2048L-USB2 are perfect for this application because of their high resolution, high speed processing capabilities, and superior throughput in the wavelengths of interest.
Avantes spectrometers can also be used to perform quality control inspection of thin film solar panels. The 100 AvaSpec-2048-USB2 is suitable for thin film metrology from 200 to 1100nm range and the AvaSpec-NIR256-1.7 can extend the range to 1750nm.
For large-scale manufacturers that prefer to incorporate spectrometers into their production control systems, Avantes OEM modules provide a low-cost solution. All Avantes instruments are supplied as OEM modules or lab instruments.
Characterization of Solar Simulators
Solar simulators serve as an important tool for test and measurement of photo-voltaic; however, their characterization can be quite complex because each manufacturer has different design features to meet the requirements of various photo-voltaic panel manufacturers.
Standards which offer testing procedures for measuring continuous and pulsed wave solar simulators include IEC 60904 Photovoltaic Devices and ASTM E927 -10 Standard Specification for Solar Simulation for Terrestrial Photovoltaic Testing. The similarity of the measured spectrum to the Air Mass 1.5 Global reference spectrum defines the type of solar simulator.
Avantes spectroradiometer systems include a spectrometer, a sampling head, and a fiber optic; the sampling head is usually an integrating sphere or a cosine diffuser. With the help of an NIST traceable source, these components are irradiance calibrated and supplied as a calibrated system.
Avantes AvaSpec Sensline of back-thinned CCD systems is perfect for this application because of the high quantum efficiency of the detectors in the NIR and UV range. Conversely, Avantes Spectroradiometer systems are specifically suitable for this application due to excellent thermal stability, high resolution provided by symmetrical Czerny-Turner optical bench, and the ability to send and receive digital and analog communication.
Avantes spectrometers are capable of collecting and storing spectra to on board RAM. This capability delivers extremely fast data collection and storage which is usually needed to define the uniformity of pulsed solar simulators.
Additionally, with the help of Avantes AS5216 DLL package, customers can develop their own code to show their adherence to the various photo- voltaic standards. The DLL package includes samples programs in Visual Basic, LabView, Delphi, C#, C++, and other programming environments.
Measurement of Direct Solar Radiation
In both research and industrial applications, measurement of direct solar radiation is very important. Avantes spectroadiometer systems are used by many university researchers and government labs to measure solar radiation.
Avantes systems are also used by industrial customers for monitoring heliostats and quantifying solar concentrators. For direct solar measurements, Avantes solutions usually include a dual channel spectrometer that covers 250-1700nm or 250-2500nm range depending on customers’ requirements. The spectrometer is fixed to the sensor head using a specialized bifurcated fiber optic cable.
The flexibility of fiber optic helps in placing the sensor head several meters away from the spectrometer, which is usually enclosed in a temperature-regulated environment. Avantes AvaSoft software helps in integrating two more spectra from each spectrometer into a combined spectrum for the range of interest.
Avantes spectroscopy And spectroradiometry systems prove useful for the characterization of solar simulator characterization, for measurement of direct solar radiation, and for monitoring and quality control of thin film production in the solar industry.
This information has been sourced, reviewed and adapted from materials provided by Avantes BV.
For more information on this source, please visit Avantes BV.