Magnesiothermically Formed Porous Silicon Thin Films on Silicon‐on‐Insulator Optical Microresonators for High‐Sensitivity Detection

Abstract

Integration of a thin uniform layer of highly porous silicon on top of ultra-compact silicon-on-insulator microresonators is experimentally demonstrated via magnesiothermic reduction, enabling increased surface area for analyte adsorption as well as high Q-factor (~22 000). The demonstrated sensitivity is ~0.8 pm (pg mm-2)-1, with an estimated detection limit of areal mass density being ~1 pg mm-2.