High Photo-to-Dark-Current Ratio in SiGe/Si Schottky-Barrier Photodetectors by Using an a-Si:H Cap Layer

Hwang, Jun–Dar; Chen, Y.H.; Kung, Chung‐Yuan; Liu, J.C.

doi:10.1109/ted.2007.901791

Cited by 25 publications

(7 citation statements)

References 23 publications

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“…Furthermore, in our previous study the a-Si 1−x Ge x :H layer will be formed between the interface of p-SiGe and a-Si:H due to Ge atoms outdiffusion during the growth of a-Si:H. The a-Si 1−x Ge x :H and passivated surface of sample C are responsible for higher photocurrent. 14 With the passivated surface and thus fewer surface states, the surface recombination velocity of the photogenerated carriers will be significantly reduced; hence, a higher photocurrent is achieved in sample C as compared to sample D. Photoresponsivities, defined as the difference between photocurrent and dark current divided by incident power, for these samples are estimated and illus-trated in Fig. 5.…”

Section: Resultsmentioning

confidence: 99%

Effects of Hydrogenated–Amorphous–Silicon Layer on the Performance of SiGe Metal–Semiconductor–Metal Photodetectors

Hwang

Chen

Kung

et al. 2007

J. Electrochem. Soc.

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A thin ͑30 nm͒ hydrogenated-amorphous-silicon ͑a-Si:H͒ layer has been introduced to dramatically suppress the dark current of SiGe/Si metal-semiconductor-metal photodetectors ͑MSM-PDs͒ and enhance their photocurrent, around 850 nm wavelength. The effects of a-Si:H as a passivation and a Schottky-barrier-height ͑SBH͒ enhancement layer on reducing the dark current of SiGe/Si MSM-PDs have been studied in detail. It was found that the a-Si:H as a passivation layer could effectively suppress the dark current better than the a-Si:H as a SBH enhancement layer. Compared to uncapped samples, the samples with a-Si:H passivation layer could enhance the photo-to-dark-current ratio and responsivity by a magnitude of 1.39 ϫ 10 6 and 21, respectively. The related mechanisms have been proposed in this paper.

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Section: Resultsmentioning

confidence: 99%

Effects of Hydrogenated–Amorphous–Silicon Layer on the Performance of SiGe Metal–Semiconductor–Metal Photodetectors

Hwang

Chen

Kung

et al. 2007

J. Electrochem. Soc.

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“…Besides, the photo-to-dark current ratio (i.e., on-off ratio), another key performance index for a photodetector, reached 5.4 × 10 3 (at 0 V with a power density of 38.2 μW cm −2 ) to be evenly matched for other reported GaN-based UV photodetectors. [41][42][43][44] Even under an extremely low power density (20 nW cm −2 ), the on-off ratio can still reach 30 (see Figure S4a, Supporting Information), revealing the ultrasensitivity of this Al-NC/GaN-TNC structure.…”

Section: Uv Photodetectionmentioning

confidence: 99%

Multifunctional Plasmonic Sensor for Excellent UV Photodetection and NO₂ Gas Sensing by an Array of Al Nanocaps on GaN Truncated Nanocones

Kuang

Dubey

Ranjan

et al. 2023

Advanced Optical Materials

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Plasmonics has been demonstrated to improve the performance of various optoelectronic devices operating in the infrared to visible wavelength regime. However, limited by optical properties of suitable plasmonic materials in ultraviolet (UV) regimes, rare works have been devoted to UV applications with plasmonic structures. This work deliberately fabricates a heterogeneous array of Al nanocaps (Al‐NC) on a wide‐bandgap semiconductor of GaN truncated nanocones (GaN‐TNC) and then presents a multifunctional plasmonic sensor for excellent UV photodetection and air‐quality‐index (AQI) gas sensing. As a UV photodetector, this work shows maximum responsivity (1.8 × 108 AW−1) and detectivity (1.2 × 1018 Jones) at the resonance wavelength of 355 nm, which based on the current knowledge, is the highest detectivity among GaN‐based UV photodetectors. Such a UV photodetector also introduces a decent response of rise time (78.3 ms) and fall time (303.5 ms), respectively. As a gas sensor, this work detects a key AQI gas of NO2 and provides a superior response of 28% and a detection limit of 500 ppb, respectively.

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“…In this study, we measured the photocurrent and darkcurrent using the unit cell sensor for parylene thicknesses in the range of 10-20 µm to study potential improvements in image quality using parylene. In addition, we estimated the P/D ratios to determine the optimal parylene thickness and examined the improvement in the SNR by comparing the parylene-free sensor and parylene-based sensors with different thicknesses [11].…”

Section: Evaluation Of Snr Through P/d Ratiomentioning

confidence: 99%

Development and evaluation of passive layer additive detector for stabilization in high-energy X-ray computerized tomography

et al. 2019

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To improve the image quality in cone-beam computerized tomography, a detector containing an insulator layer made of parylene-C was utilized in this study. In HgI 2 sensors with photoconducting materials, we analyzed the signal based on the thickness of the parylene-C layer and leakage current. In addition, we tried to evaluate the reproducibility of Hgl 2 that decreases gradually based on the continuous X-ray study. For the signal-to-noise ratio, we evaluated the photocurrent/darkcurrent (P/D) ratio according to the reduction in the leakage current. Our results indicated a detector reproducibility of 0.82% for a parylene-layer thickness of 18 µm, which represents an improvement of 0.43% over that of a "parylene-free" detector. Compared with the parylene-free sensors, the ones with a parylene layer displayed an approximately linear increase of the P/D ratio with increasing parylene layer thickness. For layers 18 or 20 µm thick this ratio, indicative of image quality, exhibited an improvement of ∼ 70 times or more in comparison to a parylene-free sensor.

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High Photo-to-Dark-Current Ratio in SiGe/Si Schottky-Barrier Photodetectors by Using an a-Si:H Cap Layer

Cited by 25 publications

References 23 publications

Effects of Hydrogenated–Amorphous–Silicon Layer on the Performance of SiGe Metal–Semiconductor–Metal Photodetectors

Effects of Hydrogenated–Amorphous–Silicon Layer on the Performance of SiGe Metal–Semiconductor–Metal Photodetectors

Multifunctional Plasmonic Sensor for Excellent UV Photodetection and NO₂ Gas Sensing by an Array of Al Nanocaps on GaN Truncated Nanocones

Development and evaluation of passive layer additive detector for stabilization in high-energy X-ray computerized tomography

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High Photo-to-Dark-Current Ratio in SiGe/Si Schottky-Barrier Photodetectors by Using an a-Si:H Cap Layer

Cited by 25 publications

References 23 publications

Effects of Hydrogenated–Amorphous–Silicon Layer on the Performance of SiGe Metal–Semiconductor–Metal Photodetectors

Effects of Hydrogenated–Amorphous–Silicon Layer on the Performance of SiGe Metal–Semiconductor–Metal Photodetectors

Multifunctional Plasmonic Sensor for Excellent UV Photodetection and NO2 Gas Sensing by an Array of Al Nanocaps on GaN Truncated Nanocones

Development and evaluation of passive layer additive detector for stabilization in high-energy X-ray computerized tomography

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Product

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Multifunctional Plasmonic Sensor for Excellent UV Photodetection and NO₂ Gas Sensing by an Array of Al Nanocaps on GaN Truncated Nanocones