Print Email Facebook Twitter Optical sensing of chlorophyll(in) with dual-spectrum Si LEDs in SOI-CMOS technology Title Optical sensing of chlorophyll(in) with dual-spectrum Si LEDs in SOI-CMOS technology Author Dutta, S. (TU Delft Dynamics of Micro and Nano Systems) Steeneken, P.G. (TU Delft Dynamics of Micro and Nano Systems) Verbiest, G.J. (TU Delft Dynamics of Micro and Nano Systems) Date 2022 Abstract Small and low-cost chlorophyll sensors are popular in agricultural sector and food-quality control.Combining such sensors with silicon CMOS electronics is challenged by the absence of silicon-integrated light-sources.We experimentally achieve optical absorption sensing of chlorophyll based pigments with silicon (Si) micro light-emitting diodes (LED) as light-source, fabricated in a standard SOI-CMOS technology.By driving a Si LED in both forward and avalanche modes of operation,we steer its electroluminescentspectrum between visible (400-900 nm) and near-infrared (1120 nm). For detection of chlorophyll in solution phase, the dualspectrum light from the LED propagates vertically through glycerol micro-droplets containing sodium copper chlorophyllin at varying relative concentrations. The transmitted light is detected via an off-chip Si photodiode. The visible to near-infrared color ratio (COR) of the photocurrent yields the effective absorption coefficient. We introduce the LED-specificmolar absorption coefficient as ametric to compute the absolute pigment concentration (0.019 ± 0.006 mol L-1) and validate the results by measurements with a hybrid spectrophotometer. With the same sensor, we also show noninvasive monitoring of chlorophyll in plant leaves. COR sensitivities $\sim 3.9 \times 10^{4}$ mol-1L and $\sim 5.3 \times 10^{4}$ mol-1L are obtained for two leaf species, where light from the LED propagates diffusely through the thickness of the leaf prior to detection by the photodiode. Our work demonstrates the feasibility of realizing fully CMOS-integrated optical sensors for biochemical analyses in food sector and plant/human health. Subject AbsorptionAvalanche breakdownchlorophyllCMOSelectroluminescenceFrequency modulationLight emitting diodeslight-emitting diodeoptical sensorOptical sensorsPigmentsSemiconductor device measurementSilicon To reference this document use: http://resolver.tudelft.nl/uuid:9e5a7ba2-72a4-42c5-b889-ad906ac757f4 DOI https://doi.org/10.1109/JSEN.2021.3086588 Embargo date 2023-07-01 ISSN 1530-437X Source IEEE Sensors Journal, 22 (12), 11280-11289 Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 S. Dutta, P.G. Steeneken, G.J. Verbiest Files PDF Optical_Sensing_of_Chloro ... nology.pdf 3.7 MB Close viewer /islandora/object/uuid:9e5a7ba2-72a4-42c5-b889-ad906ac757f4/datastream/OBJ/view