A Physical Basis for the Extrapolation of Silicon Photodiode Quantum Efficiency into the Ultraviolet

The errors associated with modelling the quantum efficiency of high quality silicon photodiodes in the ultraviolet using the semiconductor device-modelling program PC1D are discussed. Uncertainty spectra have been calculated for these errors, which are mainly a result of the application of basic solid-state models and parameters in the extreme case of ultraviolet absorption. The more critical parameters have been identified and, where possible, corrections have been made to account for them. The overall uncertainty associated with quantum efficiency modelling is found to be well below 0,2% for detection of radiation from 400 nm to 300 nm, and below 1% for radiation down to 250 nm.