Self-Filtered NIR Photodetectors Based on Silicon Micro-Holes Array for Stable Heart Rate Monitoring

Zhang, Hao; Cui, Yinghao; Lu, Mengxue; Yang, Qingyang; Feng, Jianguo; Chen, Shirong; Yang, Xiaoping; Xu, Guangqing; Yu, Yongqiang

doi:10.1109/led.2022.3216280

Cited by 7 publications

(5 citation statements)

References 22 publications

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“…When the incident photon reaches the junction region, more photogenerated carriers are separated under the action of the built-in electric field in the junction region, resulting in the formation of photocurrent. 22 The deposition time affects the densities and thicknesses of the PbS materials. Figure 4b represents the test plots for different deposition times at a ratio of lead to sulfur of 1:4 and pH = 9.5, where the incident wavelength is 1550 nm, the switching period is 10 s, and no external bias voltage is applied.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…In addition, the light-trapping effect of the silicon holes can increase the collection and absorption of near-infrared light in the device. When the incident photon reaches the junction region, more photogenerated carriers are separated under the action of the built-in electric field in the junction region, resulting in the formation of photocurrent …”

Section: Resultsmentioning

confidence: 99%

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Growth of Si/PbS Heterostructure Infrared Photodetectors for NIR Detection

Zhang,

Yang,

et al. 2024

ACS Photonics

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Lead sulfide (PbS), as an excellent narrow band gap material, has a wide range of applications in short-wave infrared detection. In this study, Si/PbS photodetectors are fabricated by an electrochemical deposition technique to grow PbS materials inside a patterned silicon window. The deposited PbS materials were characterized using SEM, TEM, and XRD. The PbS morphology and particle size were investigated by varying the electrochemical deposition time and precursor solution concentration ratio to assess the photoelectric properties. The results show that the size and thickness of the PbS material decrease with the increase of sulfur content, which also affects the photoelectric performance of the detector. When Pb: S = 1:1, the specific detectivity reaches its maximum value of 1.3 × 10 9 Jones. With the increase of the sulfur content, the responsivity and detectivity of the device decrease, but the response time is reduced. When Pb: S = 1:9, the response/recovery time is 0.25 s/0.23 s, while the dark current is as low as 1.58 × 10 −8 A. This method of optimizing the performance by modulating the size and thickness of the PbS material provides a novel approach for the development of Si/PbS heterostructure photodetectors.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Growth of Si/PbS Heterostructure Infrared Photodetectors for NIR Detection

Zhang,

Yang,

et al. 2024

ACS Photonics

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“…Figure 1 a illustrates the fabrication process of the PbS QD-coated Si MHA/Gr vdW Schottky NIR photodiode, in which the inductively coupled plasma (ICP) technique and the well-developed silicon etching technique were chosen to obtain the Si MHA [ 8 , 12 ]. The CVD-graphene was used to form a Schottky contact as the bottom electrode.…”

Section: Resultsmentioning

confidence: 99%

“…For example, a self-filtered NIR Si-based photodiode has been used as a photoplethysmography (PPG) sensor for heart rate (HR) monitoring. Notably, a more accurate HR has been with an Si-based NIR PD than that obtained by using broadband PDs from a commercial PPG system, due to the suppression of disturbances caused by ambient light [ 12 ]. Due to the need for noninvasive, inexpensive, and convenient health monitoring, PPGs have become a powerful platform for measuring physiological parameters in individuals using wearable electronics.…”

Section: Introductionmentioning

confidence: 99%

PbS QD-Coated Si Micro-Hole Array/Graphene vdW Schottky Near-Infrared Photodiode for PPG Heart Rate Measurement

Xu,

Cui,

Zhang

et al. 2023

Sensors

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Near-infrared (NIR) photodetectors (PDs) have attracted much attention for use in noninvasive medical diagnosis and treatments. In particular, self-filtered NIR PDs are in high demand for a wide range of biomedical applications due to their ability for wavelength discrimination. In this work, we designed and then fabricated a Si micro-hole array/Graphene (Si MHA/Gr) van der Waals (vdW) Schottky NIR photodiode using a PbS quantum dot (QD) coating. The device exhibited a unique self-filtered NIR response with a responsivity of 0.7 A/W at −1 V and a response speed of 61 μs, which is higher than that seen without PbS QD coating and even in most previous Si/Gr Schottky photodiodes. The light trapping of the Si MHA and the PbS QD coating could be attributed to the high responsivity of the vdW photodiode. Furthermore, the presented NIR photodiode could also be integrated in photoplethysmography (PPG) for real-time heart rate (HR) monitoring. The extracted HR was in good accord with the values measured with the patient monitor—determined by analyzing the Fourier transform of the stable and reliable fingertip PPG waveform—suggesting its potential for practical applications.

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“…Figure 1a illustrates the fabrication process of the PbS QD-coated Si MHA/Gr vdW Schottky NIR photodiode, in which the inductively coupled plasma (ICP) technique and the well-developed silicon etching technique were chosen to obtain the Si MHA [8,12]. The CVD-graphene was used to form a Schottky contact as the bottom electrode.…”

Section: Resultsmentioning

confidence: 99%

PBS QDs Coated Si Micro-Holes Array/Graphene vdW Schottky Near-Infrared Photodiode for PPG Heart-Rate Measurement

Xu¹,

Cui²,

Zhang³

et al. 2023

Preprint

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Near-infrared (NIR) photodetectors (PDs) have attracted much attention in noninvasive medical diagnosis and treatment. Especially, the self-filtered NIR PDs are highly demandable for tremendous biomedical application due to their strong ability in wavelength discrimination. In this work, we designed and then fabricated a Si micro-holes array/Graphene (Si MHA/Gr) van der Waals (vdW) Schottky NIR photodiode by using PbS quantum dots (QDs) coating. The device exhibits a unique self-filtered NIR response with a responsivity of 0.7 A/W at -1 V and a response time of 61 μs, which are higher than that without PbS QDs coating and even most of previous Si/Gr Schottky photodiodes. The light trapping of the Si MHA and the PbS QDs coating can be attributed to the high responsivity of the vdW photodiode. Furthermore, the presented NIR photodiode can also be integrated in photoplethysmography (PPG) for real-time heart-rate (HR) monitoring. The extracted HR is in great accord with the value measured with the patient monitor by analyzing the Fourier transform of the stable and reliable fingertip PPG waveform, suggesting its potential for practical applications.

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Self-Filtered NIR Photodetectors Based on Silicon Micro-Holes Array for Stable Heart Rate Monitoring

Cited by 7 publications

References 22 publications

Growth of Si/PbS Heterostructure Infrared Photodetectors for NIR Detection

Growth of Si/PbS Heterostructure Infrared Photodetectors for NIR Detection

PbS QD-Coated Si Micro-Hole Array/Graphene vdW Schottky Near-Infrared Photodiode for PPG Heart Rate Measurement

PBS QDs Coated Si Micro-Holes Array/Graphene vdW Schottky Near-Infrared Photodiode for PPG Heart-Rate Measurement

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