Structure and performance of the novel photodetector. (Credit - Aalto University)
Professor Hele Savin and a team of researchers have developed a new light detector that can trap over 96% of the photons covering UV, visible, and infrared wavelengths.
Present-day light detectors suffer from severe reflection losses as currently used 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. Low incident angle is useful especially in scintillating x-ray sensors. We also addressed electrical losses present in traditional sensors that utilize 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.
Hele Savin, Professor, Aalto University
The new concept for light detection was inspired from the team’s previous research on nanostructured solar cells. The nanostructure used in the light detector is comparable to that used by the team a few years ago in their record-breaking high efficiency black silicon solar cells.
The team awaits a patent for the new light detector. The prototype detectors are currently being tested in imaging applications connected to safety and medicine. The researchers are also continuously looking for new applications for their invention, mainly among the UV and infrared ranges that would gain from the excellent spectral response.
The research findings have been published in the November 14 issue of Nature Photonics scientific journal.