Photo and particle detectors – BFO as energy efficient detector
With BFO, new CCD and CMOS sensors can be developed for energy-efficient photo and particle detectors. An active pixel sensor is a semiconductor detector which measures light and is manufactured with CMOS technology. CCD sensors are light-sensitive electronic components that are based on the inner photoelectric effect.
CMOS and CCD sensors are distinguished by the number of pixels that share one amplifier circuit, which will read the signal respectively. In CMOS sensors, each pixel includes an amplifier circuit, in CCD sensors however individual amplifiers for multiple pixels are used. Thus, CMOS sensors have a higher sensitivity than CCD sensors regarding the shortwave infrared region, while CCD sensors in contrast have a higher sensitivity in the visible light region. Due to their high sensitivity, CCD sensors are used in astronomy or photometry, but also in general digital photography as well as in scanners and copiers. CMOS sensors are used for digital photography, video cameras, cameras in mobile phones and increasingly for safety systems in cars.
BFO-coated MOS detectors enable a new detection mechanism for photons and particles. Due to the stabilization caused by the BFO thin film, the capacity characteristics of the detectors is stabilized, so that the impingement of photons and particles causes a capacity difference, which can be measured and used to determine the number of photons or particles. For uncoated MOS detectors, the capacity is not a suitable measurement variable since the impinging photons and particles can alter the capacity of the detector so thoroughly that the capacity difference can’t be used anymore to calculate the number of photons or particles. A thin BFO film coating therefore enables a significantly more energy-efficient in-situ-detection of light and particles, up to two orders of magnitude.