Optimizing the wavelength response in one‐dimensional p‐Si Schottky barrier optical PSDs

Abstract This paper reports on the varying wavelength response of optical position detectors made of different Schottky barrier metals, titanium, tantalum and aluminium. The best sensitivities came from the titanium devices, followed by the tantalum devices and finally the aluminium devices. The most linear devices were fabricated from tantalum followed by aluminium and the worst from titanium. The devices responded well under low intensity LED illumination indicating that common and cheap light sources are suitable for producing strong linear responses in these PSDs. Long wavelength illumination usually produced the highest sensitivities, though this depended on the Schottky metal used. Titanium devices averaged an increase of 250% between the responses for short (480 nm) and long wavelength (873 nm) light. The corresponding increase for tantalum devices was 125% while it was 116% for aluminium devices.