Crystal-phase-specific near-infrared photoluminescence from Er3+-doped Bi2O3 thin films

2022 ◽  
Vol 40 (1) ◽  
pp. 013417
Author(s):  
Housei Akazawa
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Animesh Pandey ◽  
Reena Yadav ◽  
Mandeep Kaur ◽  
Preetam Singh ◽  
Anurag Gupta ◽  
...  

AbstractTopological insulators (TIs) possess exciting nonlinear optical properties due to presence of metallic surface states with the Dirac fermions and are predicted as a promising material for broadspectral phodotection ranging from UV (ultraviolet) to deep IR (infrared) or terahertz range. The recent experimental reports demonstrating nonlinear optical properties are mostly carried out on non-flexible substrates and there is a huge demand for the fabrication of high performing flexible optoelectronic devices using new exotic materials due to their potential applications in wearable devices, communications, sensors, imaging etc. Here first time we integrate the thin films of TIs (Bi2Te3) with the flexible PET (polyethylene terephthalate) substrate and report the strong light absorption properties in these devices. Owing to small band gap material, evolving bulk and gapless surface state conduction, we observe high responsivity and detectivity at NIR (near infrared) wavelengths (39 A/W, 6.1 × 108 Jones for 1064 nm and 58 A/W, 6.1 × 108 Jones for 1550 nm). TIs based flexible devices show that photocurrent is linearly dependent on the incident laser power and applied bias voltage. Devices also show very fast response and decay times. Thus we believe that the superior optoelectronic properties reported here pave the way for making TIs based flexible optoelectronic devices.


2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yiyue Zhang ◽  
Masoumeh Keshavarz ◽  
Elke Debroye ◽  
Eduard Fron ◽  
Miriam Candelaria Rodríguez González ◽  
...  

Abstract Lead halide perovskites have attracted tremendous attention in photovoltaics due to their impressive optoelectronic properties. However, the poor stability of perovskite-based devices remains a bottleneck for further commercial development. Two-dimensional perovskites have great potential in optoelectronic devices, as they are much more stable than their three-dimensional counterparts and rapidly catching up in performance. Herein, we demonstrate high-quality two-dimensional novel perovskite thin films with alternating cations in the interlayer space. This innovative perovskite provides highly stable semiconductor thin films for efficient near-infrared light-emitting diodes (LEDs). Highly efficient LEDs with tunable emission wavelengths from 680 to 770 nm along with excellent operational stability are demonstrated by varying the thickness of the interlayer spacer cation. Furthermore, the best-performing device exhibits an external quantum efficiency of 3.4% at a high current density (J) of 249 mA/cm2 and remains above 2.5% for a J up to 720 mA cm−2, leading to a high radiance of 77.5 W/Sr m2 when driven at 6 V. The same device also shows impressive operational stability, retaining almost 80% of its initial performance after operating at 20 mA/cm2 for 350 min. This work provides fundamental evidence that this novel alternating interlayer cation 2D perovskite can be a promising and stable photonic emitter.


2012 ◽  
Vol 185 ◽  
pp. 60-64
Author(s):  
Min Min Zhu ◽  
Ze Hui Du ◽  
Jan Ma

(100)-oriented PLZT ((Pb1-x, Lax) (Zry,Ti1-y)1-x/4O3, x/y=9/65) films of up to ~ 1.23 μm have been developed on LaAlO3single crystal substrate by magnetron sputtering. The as-grown PLZT thin films exhibit high optical transparency in visible and near-infrared light wavelength and high quadratic (Kerr) EO coefficients. Prism coupler measurements reveal that the PLZT thin films possess large refractive index, as high as 2.524 in TE model and 2.481 in TM model. The transparency of >70% in the range of λ= 500-1200 nm, the optic band gap of 3.42 eV and the quadratic electro-optic (EO) coefficient of 3.38 x 10-17(m/V)2have been measured in the films. Due to the large EO coefficient and the micrometric thickness, the as-developed PLZT films have great potential in developing longitudinal-or transverse-type EO devices in electric and optic field


1989 ◽  
Vol 22 (2) ◽  
pp. 323-326 ◽  
Author(s):  
H Lengfellner ◽  
K F Renk ◽  
P Fickenscher ◽  
W Schindler

Coatings ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 248 ◽  
Author(s):  
Benjamin Schumm ◽  
Thomas Abendroth ◽  
Saleh A. Alajlan ◽  
Ahmed M. Almogbel ◽  
Holger Althues ◽  
...  

Multilayered nanocoatings allow outstanding properties with broad potential for glazing applications. Here, we report on the development of a multilayer nanocoating for zinc oxide (ZnO) and antimony doped tin oxide (ATO). The combination of ZnO and ATO thin films with their promising optical properties is a cost-efficient alternative for the production of energy-efficient glazing. It is an effective modification of the building envelope to reduce current high domestic demand of electrical power for air conditioning, especially in hot climates like Saudi Arabia. In this paper, we report the development of a nanocoating based on the combination of ZnO and ATO. Principle material and film investigations were carried out on lab-scale by dip coating with chemical solution deposition (CSD), while with regard to production processes, chemical vapor deposition (CVD) processes were evaluated in a second stage of the film development. It was found that with both processes, high-quality thin films and multilayer coatings with outstanding optical properties can be prepared. While keeping the optical transmission in the visible range at around 80%, only 10% of the NIR (near infrared) and below 1% of UV (ultraviolet) light passes these coatings. However, in contrast to CSD, the CVD process allows a free combination of the multilayer film sequence, which is of high relevance for production processes. Furthermore, it can be potentially integrated in float glass production lines.


2020 ◽  
Vol 220 ◽  
pp. 01019
Author(s):  
Elvira Fazalova ◽  
Konstantin Kochunov ◽  
Elena Bodyago ◽  
Georgii Konoplev ◽  
Nikolay Mukhin ◽  
...  

Optical and photoelectric properties of poly (ohydroxyamide) (PHA) sensitized with zinc phthalocyanines were investigated in the visible and near infrared spectral regions. The structures were deposited on glass substrates by centrifugation and subsequent drying of a PHA film without thermal annealing. Optical spectra revealed characteristic absorption peaks of phthalocyanine in the longer wavelength region at 620-640 nm and 680-700 nm; absorption of the PHA matrix monotonously increases to the shorter wavelengths starting from 700 nm. Measurements of the photocurrent under irradiation with a high-power LED at a wavelength 630 nm showed photoconductivity related to the organic dye; photoconductivity also was observed while irradiated at 540 nm, presumably due to the absorption of PHA matrix. For non-sensitized (dye-free) PHA films no detectable photocurrents were produced by 630 nm irradiation. It was shown that introducing of phthalocyanines significantly improves optical absorption and photoconductivity of PHA thin films at the wavelengths, where the maximum in the spectral distribution of solar radiation lies. It was concluded that phthalocyanine-sensitized PHA has the potential use as a photosensitive organic material for solar applications, for example in developing composite organicinorganic structures with ferroelectrics.


2015 ◽  
Vol 39 (1) ◽  
pp. 25-30 ◽  
Author(s):  
A Hasnat Rubel ◽  
J Podder

Aluminium doped cadmium sulphide thin films were prepared on glass substrate using aqueous solution of cadmium sulphide and thiourea salts by spray pyrolysis deposition (SPD) technique. Its optical properties were analyzed as a function of doping concentration. The direct energy band-gap of Al-doped CdS films was estimated in the range of 2.25 to 2.48 eV. The optical spectra of Cd1-xAlxS ternary system exhibit high absorption near visible region and transmission throughout the near-infrared region (600 - 1200 nm). Thus so obtained hetero-junction films are suitable for fabrication of photo detectors, solar cells and other optoelectronics devices.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 1, 25-30, 2015


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