A low‐power sensor for volatile organic compounds based on porous silicon photonic crystals

A miniaturized, low-power chemical sensor for volatile organic compounds using a porous Si photonic crystal is demonstrated. The device uses simple electronic circuitry a light-emitting diode, a phototransistor, and thin film of a 1-dimensional photonic crystal of porous Si, drawing 0.5 W of power. Integration of the freestanding porous silicon film with the conventional circuitry is discussed as well as the current detection limits for ethanol vapor in air.