A research team at Aalto University in Finland, led by Professor Hele Savin, says it has developed a light detector that can capture more than 96% of the photons covering visible, ultraviolet and infrared wavelengths.
“Present day light detectors suffer from severe reflection losses as [their] antireflection coatings are limited to specific wavelengths and a fixed angle of incidence. Our detector captures light without such limitations by taking advantage of a nanostructured surface,” said Prof Savin. He added the detector’s low incident angle is especially useful in scintillating x-ray sensors.
“We also addressed electrical losses in traditional sensors that use semiconductor pn-junctions for light collection. Our detector does not need any dopants to collect light; instead, we use an inversion layer generated by atomic layer deposited thin film.”
The work derives from the team’s earlier research on nanostructured solar cells and the nanostructure used in the light detector is similar to that used by the team to create black silicon solar cells with record efficiencies.
Prototype detectors are being tested in medical and safety related imaging applications related to medicine and safety, but the team is seeking new applications for its invention, especially those in the ultraviolet and infrared regions that would benefit from better spectral response.
Author
Graham Pitcher
Source: www.newelectronics.co.uk