Silicon Photodiode Detectors with Integrated Filters for VUV Solar Observations

Fabrication of stable, nearly 100% internal carrier collection efficiency silicon photodiodes (AXUV diodes) for 1 nm to 600 nm photons was successfully demonstrated by us several years ago. Owing to their excellent characteristics, these devices are being used by NIST as transfer standards in 5 nm to 250 nm range and aboard SOHO, SNOE and TIMED instruments for the EUV solar spectrum studies. Although, AXUV devices are being used in the present GOES EUV instrument, detectors for the 50 to 100 nm passband with stability and solar blindness required by GOES mission have not yet been demonstrated. Objective of this research is to realize AXUV diodes with Sn and In directly deposited filters for the 500 to 100 nm spectral region. In Phase I, fabrication of filtered diodes with five orders of magnitude visible light blocking will be demonstrated. In phase II, these devices with seven orders of magnitude visible light blocking and acceptable stability will be realized so that they will be useful with the transmission gratings to make the measurements desired by NOAA.