scholarly journals Understanding the Impact of Bismuth Heterovalent Doping on the Structural and Photophysical Properties of CH 3 NH 3 PbBr 3 Halide Perovskite Crystals with Near‐IR Photoluminescence

2019 ◽  
Vol 25 (21) ◽  
pp. 5480-5488 ◽  
Author(s):  
Rui Meng ◽  
Guangbao Wu ◽  
Jiyu Zhou ◽  
Huiqiong Zhou ◽  
Honghua Fang ◽  
...  
Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 209
Author(s):  
Gopi Chandra Adhikari ◽  
Saroj Thapa ◽  
Yang Yue ◽  
Hongyang Zhu ◽  
Peifen Zhu

All-inorganic lead halide perovskite (CsPbX3) nanocrystals (NCs) have emerged as a highly promising new generation of light emitters due to their extraordinary photophysical properties. However, the performance of these semiconducting NCs is undermined due to the inherent toxicity of lead and long-term environmental stability. Here, we report the addition of B-site cation and X-site anion (pseudo-halide) concurrently using Ba(SCN)2 (≤50%) in CsPbX3 NCs to reduce the lead and improve the photophysical properties and stability. The as-grown particles demonstrated an analogous structure with an almost identical lattice constant and a fluctuation of particle size without altering the morphology of particles. Photoluminescence quantum yield is enhanced up to near unity (~98%) by taking advantage of concomitant doping at the B- and X-site of the structure. Benefitted from the defect reductions and stronger bonding interaction between Pb2+ and SCN− ions, Ba(SCN)2-based NCs exhibit improved stability towards air and moisture compared to the host NCs. The doped NCs retain higher PLQY (as high as seven times) compared to the host NCs) when stored in an ambient atmosphere for more than 176 days. A novel 3D-printed multiplex color conversion layer was used to fabricate a white light-emitting diode (LED). The obtained white light shows a correlated color temperature of 6764 K, a color rendering index of 87, and luminous efficacy of radiation of 333 lm/W. In summary, this work proposes a facile route to treat sensitive lead halide perovskite NCs and to fabricate LEDs by using a low-cost large-scale 3-D printing method, which would serve as a foundation for fabricating high-quality optoelectronic devices for near future lighting technologies.


2011 ◽  
Vol 516 (1-3) ◽  
pp. 45-50 ◽  
Author(s):  
Christian Kuhnt ◽  
Michael Karnahl ◽  
Sven Rau ◽  
Michael Schmitt ◽  
Benjamin Dietzek ◽  
...  

2015 ◽  
Vol 8 (8) ◽  
pp. 3433-3445 ◽  
Author(s):  
J. R. Worden ◽  
A. J. Turner ◽  
A. Bloom ◽  
S. S. Kulawik ◽  
J. Liu ◽  
...  

Abstract. Evaluating surface fluxes of CH4 using total column data requires models to accurately account for the transport and chemistry of methane in the free troposphere and stratosphere, thus reducing sensitivity to the underlying fluxes. Vertical profiles of methane have increased sensitivity to surface fluxes because lower tropospheric methane is more sensitive to surface fluxes than a total column, and quantifying free-tropospheric CH4 concentrations helps to evaluate the impact of transport and chemistry uncertainties on estimated surface fluxes. Here we demonstrate the potential for estimating lower tropospheric CH4 concentrations through the combination of free-tropospheric methane measurements from the Aura Tropospheric Emission Spectrometer (TES) and XCH4 (dry-mole air fraction of methane) from the Greenhouse gases Observing SATellite – Thermal And Near-infrared for carbon Observation (GOSAT TANSO, herein GOSAT for brevity). The calculated precision of these estimates ranges from 10 to 30 ppb for a monthly average on a 4° × 5° latitude/longitude grid making these data suitable for evaluating lower-tropospheric methane concentrations. Smoothing error is approximately 10 ppb or less. Comparisons between these data and the GEOS-Chem model demonstrate that these lower-tropospheric CH4 estimates can resolve enhanced concentrations over flux regions that are challenging to resolve with total column measurements. We also use the GEOS-Chem model and surface measurements in background regions across a range of latitudes to determine that these lower-tropospheric estimates are biased low by approximately 65 ppb, with an accuracy of approximately 6 ppb (after removal of the bias) and an actual precision of approximately 30 ppb. This 6 ppb accuracy is consistent with the accuracy of TES and GOSAT methane retrievals.


2019 ◽  
Vol 4 (5) ◽  
pp. 1045-1052 ◽  
Author(s):  
Jie Chen ◽  
Ziyu Luo ◽  
Yongping Fu ◽  
Xiaoxia Wang ◽  
Kyle J. Czech ◽  
...  

2020 ◽  
Vol 496 (4) ◽  
pp. 4266-4275
Author(s):  
J A van den Born ◽  
W Jellema

ABSTRACT MICADO, a near-infrared imager for the Extremely Large Telescope, is being designed to deliver diffraction limited imaging and 50 microarcsecond (μas) astrometric accuracy. MICADO employs an atmospheric dispersion corrector (ADC) to keep the chromatic elongation of the point spread function (PSF) under control. We must understand the dispersion and residuals after correction to reach the optimum performance. Therefore, we identified several sources of chromatic dispersion that need to be considered for the MICADO ADC. First, we compared common models of atmospheric dispersion to investigate whether these models remain suitable for MICADO. We showed that the differential dispersion between common atmospheric models and integration over the full atmosphere is less than 10 μas for most observations in H band. We then performed an error propagation analysis to understand the uncertainty in the atmospheric dispersion as a function of atmospheric conditions. In addition, we investigated the impact of photometric colour on the astrometric performance. While the differential refraction between stars within the same field of view can be significant, the inclusion of an ADC rendered this effect negligible. For MICADO specifically, we found that the current optomechanical design dominates the residual dispersion budget of 0.4 milliarcseconds (mas), with a contribution of 0.31 mas due to the positioning accuracy of the prisms and up to 0.15 mas due to a mismatch between the dispersive properties of the glass and the atmosphere. We found no showstoppers in the design of the MICADO ADC for achieving 50 μas relative astrometric accuracy.


2019 ◽  
Vol 10 (4) ◽  
pp. 1901350
Author(s):  
Claire Greenland ◽  
Adam Shnier ◽  
Sai K. Rajendran ◽  
Joel A. Smith ◽  
Onkar S. Game ◽  
...  

2018 ◽  
Vol 9 (18) ◽  
pp. 5408-5411 ◽  
Author(s):  
Olga A. Lozhkina ◽  
Anna A. Murashkina ◽  
Vladimir V. Shilovskikh ◽  
Yury V. Kapitonov ◽  
Vladimir K. Ryabchuk ◽  
...  

Author(s):  
Asiyeh Shahraki ◽  
Ali Ebrahimi ◽  
Shiva Rezazadeh ◽  
Roya Behazin

The impact of ion-π interactions on the photophysical properties of quinizarin have been investigated using the density functional theory and time-dependent density functional theory at the M06-2X/6-311++G(d,p) level in the gas phase and solution.


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