scholarly journals Angle-insensitive amorphous silicon optical filter for fluorescence contact imaging

2018 ◽  
Vol 43 (3) ◽  
pp. 354 ◽  
Author(s):  
Efthymios P. Papageorgiou ◽  
Hui Zhang ◽  
Bernhard E. Boser ◽  
Catherine Park ◽  
Mekhail Anwar
2018 ◽  
Vol 9 ◽  
pp. 2788-2793 ◽  
Author(s):  
Daiming Liu ◽  
Qingkang Wang ◽  
Qing Wang

The wastage of near-infrared light seriously restricts the photoelectric conversion efficiency of hydrogenated amorphous silicon (a-Si:H) thin film solar cells. Spectral upconversion is of great significance in reducing the wastage. Herein, the upconverting compound NaYF4:Yb3+/Er3+ was synthesized via a hydrothermal method. SEM and XRD results revealed the morphology and a phase transition from cubic to hexagonal NaYF4. Photoluminescence spectra indicated that the hexagonal NaYF4:Yb3+/Er3+ nanorods convert near-infrared light of 980 nm to the visible light with wavelength peaks at 654, 541 and 522 nm. Hence, the upconverting rods were incorporated in a polymethylmethacrylate (PMMA) layer on the rear side of a-Si:H solar cell. Under AM1.5 solar irradiation, a facile optical filter was used to scrutinize the effect of upconversion on the cell performance. Compared with a bare cell, the NaYF4:Yb3+/Er3+-based a-Si:H cell exhibited an 25% improved short-circuit current and an appreciable improvement of the near-infrared response of the external quantum efficiency. Moreover, because the size of the nanorods is comparable to the wavelength of visible light, the rods effectively scattered light, thus enhancing the visible light harvesting.


Nature ◽  
2021 ◽  
Vol 589 (7840) ◽  
pp. 22-23
Author(s):  
Paul F. McMillan

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.


1981 ◽  
Vol 42 (C4) ◽  
pp. C4-663-C4-666
Author(s):  
X. B. Liao ◽  
G. L. Kong ◽  
X. R. Yang ◽  
P. D. Wang ◽  
Y. Q. Chao ◽  
...  

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-54-C6-56 ◽  
Author(s):  
S. T. Kshirsagar ◽  
J. S. Lannin

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