Significant photodiode quantum efficiency improvement and spectral response alteration through surface effects in vacuum

Surface effects stemming simply from photodiode operation in vacuum environment are seen to improve quantum efficiency significantly. This is attributed to desorption of surface impurities and consequent reduction of surface recombination and Debye length. Effective depletion layer width, because of junction shallowness, can also be noticeably affected by changes in surface potential and free charge redistribution stemming from desorption of surface impurities. Quantum efficiency enhancement here in vacuum is greatest at visible wavelengths, thus suggesting application in solar cell technology, particularly since Isc, Voc, and fill factor are all increased in vacuum.