Dark-Current-Blocking Mechanism in BIB Far-Infrared Detectors by Interfacial Barriers

Pan, Changyi; Yin, Ziwei; Song, Zhiyong; Yao, Yao; Zhang, Yi; Hao, Jiaming; Kang, Ting-Ting; Deng, Huiyong; Wu, Huizhen; Dai, Ning

doi:10.1109/ted.2021.3072359

Cited by 6 publications

(2 citation statements)

References 33 publications

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“…First, the black Si has a large number of surface defects − that reduce carrier lifetime and increase surface recombination and dark current. Second, the defect energy band acts as an additional channel for dark current, which is a common problem in BDA-type PD for mid- and far-IR detection. , Therefore, to improve the performance of the device, it is necessary to passivate the surface defects and reduce the dark current density.…”

Section: Resultsmentioning

confidence: 99%

“…After the introduction of ZnO, electrons in the defect band are blocked by the ZnO bandgap, causing the reduction of dark current. This is an effect of BIB (blocked impurity band) applied in the BDA mid- and far-IR detection. , Under illumination, electrons in the defect band absorb the NIR light and transit to the conduction band of Si to form photocurrent. Since the positions of the ZnO conduction band and Si conduction band are close, only a small band bending occurs in the contact region between ZnO and Si, allowing most photoelectrons driven by the bias to pass through ZnO to the rear electrode.…”

Section: Resultsmentioning

confidence: 99%

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Bulk Defect-Mediated Absorption Sub-Bandgap All-Silicon Photodetector with Low Dark Current Density at Ambient Temperatures

Wu,

Yu,

Dai

et al. 2023

ACS Photonics

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In this work, we made a bulk defect-mediated absorption (BDA) sub-bandgap all-Si photodetector (PD) with low dark current density and high detectivity at ambient temperatures (223–293 K). The testing wavelength is chosen as 1319 nm. Pt layer was deposited onto the surface of black Si, followed by annealing at 950 °C, to form a bulk defect energy band for sub-bandgap near-infrared (NIR) absorption. The Al2O3 layer was applied to the front side of the PD as a typical passivating layer to passivate the surface of the black Si. The ZnO layer was applied to the rear side of the PD to block the dark current arising from the introduced bulk defect band. The synergetic introduction of the passivating and blocking layers reduced the dark current significantly by 2 to 3 orders of magnitude. For the PD after thickness optimization of passivating and blocking layers in this work, at 293 and 223 K, the dark current densities finally achieved were 6.0 × 10–8 and 1.6 × 10–9 A/cm2, with responsivities of 3.9 and 2.9 mA/W and specific detectivities of 2.8 × 1010 and 1.2 × 1011 cm·(Hz)1/2/W, respectively, at a bias of 0.3 V. The all-Si NIR PD developed here would have promising applications in cost-effective, low-light-level, NIR detection and imaging.

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