Photothermal Absorption Spectrometer for Cost Reduction in PV Materials
Summary
The Photothermal absorption spectrometer for cost reduction in PV materials project acknowledges that eliminating defects in PV materials is critical for high-efficiency devices and therefore a low cost per watt. Often researchers are unable to measure the optical absorption fingerprint that contains critical information, such as sub-bandgap contaminants and Urbach tails. A correct measurement would require commercially available instruments to be about 100x more sensitive.We have built a Photothermal Deflection Spectrometer (PDS) that measures optical absorption with 100x to 1000x higher sensitivity than commercial systems, enabling PV labs and manufacturers to finally identify and address efficiency-limiting defects. The contactless nature of our instrument means it can be applied end-to-end across the entire PV value chain.At a research level, our lab prototype has become a necessity for the perovskite and CZTS groups at UNSW. An early industrial prototype was completed in 2018.The Photothermal absorption spectrometer for cost reduction in PV materials project aims to: build a demonstration unit for customer demonstrations, limited measurement service and to gain practical experience from our designWe envision that PDS could become a standard tool in every PV research institute and quality assurance laboratory around the world, and thus accelerate further reduction in the cost per watt.