Conductive Distributed Bragg Reflector Fabricated at Low Temperature

A conductive DBR electrode fabricated using the single Indium tin oxide (ITO) conductive material is proposed. The high refractive index of the dense ITO film was achieved by RF sputtering at room temperature and the porous ITO film with low refractive index was prepared by applying supercritical CO2(SCCO2) treatment at 60 °C on gel-coated ITO thin films. The index contrast of the ITO bilayers was higher than 0.5 at a wavelength of 550 nm. In addition, small deviations on the optical thickness of the ITO bilayers were observed during the DBR stacking processes. For the DBR comprising 4 periods ITO bilayers, the reflectance and sheet resistance of 72.8% and 35 Ω/ were achieved.

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Extended bound states in the continuum in a one-dimensional grating implemented on a distributed Bragg reflector

Nanophotonics ◽

10.1515/nanoph-2021-0478 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Emilia Pruszyńska-Karbownik ◽

Mikołaj Janczak ◽

Tomasz Czyszanowski

Keyword(s):

Refractive Index ◽

Bound States ◽

High Refractive Index ◽

Bragg Reflector ◽

Distributed Bragg Reflector ◽

Optical Cavities ◽

One Dimensional ◽

Optical Modes ◽

High Degree ◽

The Continuum

Abstract Bound states in the continuum (BICs) are observed in optical cavities composed of a high refractive index periodic structure embedded in significantly lower refractive index surroundings, enabling vertical confinement of the grating modes. Here, we propose a vertically nonsymmetric configuration, implemented on a high refractive index bulk substrate with a one-dimensional grating positioned on a distributed Bragg reflector (DBR). In this configuration, the grating modes are leaky, which could prohibit the creation of a BIC if the grating was implemented on uniform substrate. However, the judiciously designed DBR on which the grating is implemented reflects nonzero diffraction orders induced by the grating. We found that the laterally antisymmetric optical modes located at the center of the Brillouin zone of this structure create BICs that are robust against changes in the grating parameters, as long as the DBR reflects the diffraction orders. The configuration enables a high degree of design freedom, facilitating the realization of very high quality factor cavities in conventional all-semiconductor technology.

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Determination of Reactive RF-Sputtering Parameters for Fabrication of SiOx Films With Specified Refractive Index, for Highly Reflective SiOx Distributed Bragg Reflector

IEEE Photonics Journal ◽

10.1109/jphot.2017.2649500 ◽

2017 ◽

Vol 9 (1) ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Elnaz Afsharipour ◽

Byoungyoul Park ◽

Cyrus Shafai

Keyword(s):

Refractive Index ◽

Rf Sputtering ◽

Bragg Reflector ◽

Distributed Bragg Reflector

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Improving Performance of CIGS Solar Cells by Annealing ITO Thin Films Electrodes

International Journal of Photoenergy ◽

10.1155/2015/483147 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Chuan Lung Chuang ◽

Ming Wei Chang ◽

Nien Po Chen ◽

Chung Chiang Pan ◽

Chung Ping Liu

Keyword(s):

Thin Films ◽

Optical Properties ◽

Solar Cells ◽

Indium Tin Oxide ◽

Copper Indium Gallium Diselenide ◽

Glass Substrates ◽

Ito Film ◽

Ito Thin Films ◽

Cigs Solar Cells ◽

Ito Films

Indium tin oxide (ITO) thin films were grown on glass substrates by direct current (DC) reactive magnetron sputtering at room temperature. Annealing at the optimal temperature can considerably improve the composition, structure, optical properties, and electrical properties of the ITO film. An ITO sample with a favorable crystalline structure was obtained by annealing in fixed oxygen/argon ratio of 0.03 at 400°C for 30 min. The carrier concentration, mobility, resistivity, band gap, transmission in the visible-light region, and transmission in the near-IR regions of the ITO sample were-1.6E+20 cm−3,2.7E+01 cm2/Vs,1.4E-03 Ohm-cm, 3.2 eV, 89.1%, and 94.7%, respectively. Thus, annealing improved the average transmissions (400–1200 nm) of the ITO film by 16.36%. Moreover, annealing a copper-indium-gallium-diselenide (CIGS) solar cell at 400°C for 30 min in air improved its efficiency by 18.75%. The characteristics of annealing ITO films importantly affect the structural, morphological, electrical, and optical properties of ITO films that are used in solar cells.

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