Fabrication and characterization of Au/n-Si photodiode with lithium as back-surface-field

In this work, we present a design and characterization of Schottky barrier Au/n-Si/Li based UV–VIS photodiode for application, such as solar UV monitoring, flame sensors and UV astronomy. The Schottky photodiode was realized with a thin layer of gold (Au) at the front side of high purity n-type silicon and lithium (Li) on the back side as back-surface-field (Li-BSF). The Li-BSF used was a new method which allow us to modulate and choice the depletion width. I–V characteristic, capacitance and spectral response were performed, the results were found in agreement with those determined by simulation method. A quantum efficiency (QE) of 47% at about 550 nm wavelength was obtained using only a thin gold layer as sensitive area. The thickness of gold used on the photodiode was around 125 Å, where 58% of light transmission was carried out.