Optocoupling in CMOS

Agarwal, Vishal; Dutta, Satadal; Annema, Anne-Johan; Hueting, R.J.E.; Schmitz, Jurriaan; Lee, M.J.; Charbon, Edoardo; Nauta, Bram

doi:10.1109/iedm.2018.8614523

Cited by 15 publications

(8 citation statements)

References 6 publications

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“…Interestingly, Si p-n junction diodes exhibit broad-spectrum electroluminescence (EL) near 1120 nm in forward mode (FM) and in the range of 400 nm -900 nm in avalanche mode (AM) of operation, although at a very low quantum efficiency (~10 -3 -10 -5 ) [12]- [17] due to the indirect bandgap of Si. Recent advancements [18]- [20] have successfully highlighted the Si LED as a promising candidate for monolithically integrated optical interconnects due to the high responsivity of Si photodiodes (PDs) for wavelengths (λ) < 1000 nm.…”

Section: Introductionmentioning

confidence: 99%

Optical absorption sensing with dual-spectrum silicon LEDs in SOI-CMOS technology

2020

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Silicon p-n junction diodes emit low-intensity, broad-spectrum light near 1120 nm in forward bias and between 400-900 nm in reverse bias (avalanche). For the first time, we experimentally achieve optical absorption sensing of pigment in solution with silicon micro LEDs designed in a standard silicon-on-insulator CMOS technology. By driving a single LED in both forward and avalanche modes of operation, we steer it's electroluminescent spectrum between visible and near-infrared (NIR). We then characterize the vertical optical transmission of both visible and NIR light from the LED through the same micro-droplet specimen to a vertically mounted discrete silicon photodiode. The effective absorption coefficient of carmine solution in glycerol at varying concentrations were extracted from the color ratio in optical coupling. By computing the LED-specific molar absorption coefficient of carmine, we estimate the concentration (~0.040 mol L -1 ) and validate the same with a commercial spectrophotometer (~0.030 mol L -1 ). With a maximum observed sensitivity of ~1260 cm -1 mol -1 L, the sensor is a significant step forward towards low-cost CMOS-integrated optical sensors with silicon LED as the light source intended for biochemical analyses in food sector and plant/human health.

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Section: Introductionmentioning

confidence: 99%

Optical absorption sensing with dual-spectrum silicon LEDs in SOI-CMOS technology

2020

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“…Although this EL occurs at a low quantum efficiency (∼ 10 −3 -10 −5 ) [20]- [26] due to the indirect bandgap of Si, for many applications the advantages of CMOS integration of the LED outweigh the drawback of low efficiency. Recent advancements [27]- [29] have successfully highlighted the Si LED as a promising candidate for monolithically integrated optical interconnects due to the high responsivity of Si photodiodes (PDs) for wavelengths (λ) < 1000 nm. The ability to electrically switch between visible (VIS) and nearinfrared (NIR) emission from a single Si LED eliminates the need for any process modification or device replacement in an optical sensor.…”

Section: (And References Therein) Ismentioning

confidence: 99%

Optical Sensing of Chlorophyll(in) With Dual-Spectrum Si LEDs in SOI-CMOS Technology

2022

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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 electroluminescent spectrum between visible (400-900 nm) and near-infrared ( ∼ 1120 nm). For detection of chlorophyll in solution phase, the dual-spectrum 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-specific molar absorption coefficient as a metric 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 non-invasive monitoring of chlorophyll in plant leaves. COR sensitivities of ∼ 3.9×10 4 mol −1 L and ∼ 5.3×10 4 mol −1 L 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.

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“…The AM-EL of Si has a significant spectral overlap with the responsivity of Si photodiodes [7], [13], with the range of human vision [14], and with the absorption spectrum of various biochemical entities [15], [16]. As such, despite the low optical power efficiency (η opt ∼10 −6 ), AM Si LEDs have successfully emerged as light-sources in monolithic optical interconnects [5], [8], [17], pigment sensors [18], and CMOS micro-displays [11]. The performance metrics in such endapplications, e.g.…”

Section: Introductionmentioning

confidence: 99%

Avalanche-Mode Si Light-Emitting Transistor for Narrow-Band Emission Near 760 nm

Dutta

Hueting

Verbiest

2022

IEEE Electron Device Lett.

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We report an avalanche-mode light-emitting transistor (AMLET) in silicon (Si), based on a lateral bipolar junction, which emits light near 760 nm optical wavelength with a record low bandwidth of 38 nm. The AMLET, designed in a CMOS-compatible silicon-on-insulator (SOI) photonics platform, is optically confined within a 0.21 µm thick SOI layer, which forms a Fabry-P érot (FP) resonator perpendicular to the Si surface. Light is emitted from the reverse biased emitter-base junction via phonon-assisted hot carrier recombination and, additionally, minority carriers are injected via the forward-biased Base-Collector junction. The combination of injection from collector terminal through a narrow base and FP optical resonance, yields a high optical power efficiency of 4.3×10 −6 at V BC = 0.8 V and V EB = 10 V. Our work opens new possibilities in spectralengineering of Si light-emitters, which could boost performance of all-Si optical interconnects and sensors.

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Optocoupling in CMOS

Cited by 15 publications

References 6 publications

Optical absorption sensing with dual-spectrum silicon LEDs in SOI-CMOS technology

Optical absorption sensing with dual-spectrum silicon LEDs in SOI-CMOS technology

Optical Sensing of Chlorophyll(in) With Dual-Spectrum Si LEDs in SOI-CMOS Technology

Avalanche-Mode Si Light-Emitting Transistor for Narrow-Band Emission Near 760 nm

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