High UV Sensitivity in Graphene-Silicon Schottky Photodiodes in Industry Standard Packaging

Graphene is of great scientific and commercial interest due to its unique physical properties, including exceptionally high carrier mobility and light transparency over a wide wavelength range. Graphene forms a heterojunction with silicon, which can result in a Schottky barrier diode with a depletion region that extends into the silicon. These diodes can act as photodetectors because photons entering the depletion region generate electron-hole pairs, which are separated and contribute to a photocurrent. Although graphene-silicon Schottky photodiodes (GSSDs) have been investigated for over a decade, their maturity for commercial application has yet to be demonstrated. Here, we applied industry-standard semiconductor encapsulation techniques to our GSSDs and investigated devices in commercially available packages. Our GSSDs show significantly higher responsivities in the ultraviolet spectrum than commercially available silicon photodetectors before and after packaging. Moreover, packaged GSSDs greatly outperform commercial gallium nitride photodetectors and match the responsivities of silicon carbide photodiodes in the UV range. The packaged devices additionally underwent three industrial lifetime stress tests. They showed stable dark- and photocurrents for over 900 hours, passing the harsh conditions of industrial stress tests. Overall, our results demonstrate the potential of GSSDs as promising alternatives to conventional photodiodes.