Gas detection based on quantum dot LEDs utilizing differential optical absorption spectroscopy

Abstract

Near-infrared quantum dot light emitting diodes (QD-LEDs) were adopted to detect acetylene and ammonia based on differential optical absorption spectroscopy (DOAS). Three sizes of PbSe QDs were loaded on three GaN LED chips respectively to fabricate a near-infrared light source with three wavelengths and each could be modulated separately. An optical detector was used instead of a spectrograph to reduce the complexity of the detection system. The corresponding detection limits for two gases were both 10 ppm, with an accuracy of 2%.