Real-Time In Situ Observation of Microstructural Change in Organometal Halide Perovskite Induced by Thermal Degradation

2018 ◽  
Vol 28 (42) ◽  
pp. 1804039 ◽  
Author(s):  
Tae Woong Kim ◽  
Naoyuki Shibayama ◽  
Ludmila Cojocaru ◽  
Satoshi Uchida ◽  
Takashi Kondo ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Real Time ◽  
Microstructural Change ◽  
In Situ Observation ◽  
Organometal Halide Perovskite ◽  
Halide Perovskite

scholarly journals In-situ observation of trapped carriers in organic metal halide perovskite films with ultra-fast temporal and ultra-high energetic resolutions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kanishka Kobbekaduwa ◽  
Shreetu Shrestha ◽  
Pan Adhikari ◽  
Exian Liu ◽  
Lawrence Coleman ◽  
...  
Keyword(s):  
Cross Sections ◽  
High Energy ◽  
High Energy Resolution ◽  
In Situ Observation ◽  
Trap States ◽  
Tunneling Mechanism ◽  
Photocurrent Spectroscopy ◽  
Metal Halide Perovskite ◽  
Halide Perovskite

AbstractWe in-situ observe the ultrafast dynamics of trapped carriers in organic methyl ammonium lead halide perovskite thin films by ultrafast photocurrent spectroscopy with a sub-25 picosecond time resolution. Upon ultrafast laser excitation, trapped carriers follow a phonon assisted tunneling mechanism and a hopping transport mechanism along ultra-shallow to shallow trap states ranging from 1.72–11.51 millielectronvolts and is demonstrated by time-dependent and independent activation energies. Using temperature as an energetic ruler, we map trap states with ultra-high energy resolution down to < 0.01 millielectronvolt. In addition to carrier mobility of ~4 cm2V−1s−1 and lifetime of ~1 nanosecond, we validate the above transport mechanisms by highlighting trap state dynamics, including trapping rates, de-trapping rates and trap properties, such as trap density, trap levels, and capture-cross sections. In this work we establish a foundation for trap dynamics in high defect-tolerant perovskites with ultra-fast temporal and ultra-high energetic resolution.

The Copernicus global 1/12° oceanic and sea ice reanalysis

2021 ◽  
Author(s):  
Jean-Michel Lellouche ◽  
Romain Bourdalle-Badie ◽  
Eric Greiner ◽  
Gilles Garric ◽  
Angelique Melet ◽  
...  
Keyword(s):  
Sea Ice ◽  
Real Time ◽  
Sea Level ◽  
Observation System ◽  
Small Scale ◽  
Free Access ◽  
In Situ Observation ◽  
Seasonal Forecasts ◽  
Concentration Data

&lt;p&gt;The GLORYS12V1 system is a global eddy-resolving physical ocean and sea ice reanalysis at 1/12&amp;#176; resolution covering the 1993-present altimetry period, designed and implemented in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS). All the essential ocean physical variables from this reanalysis are available with free access through the CMEMS data portal.&lt;/p&gt;&lt;p&gt;The GLORYS12V1 reanalysis is based on the current CMEMS global real-time forecasting system, apart from a few specificities that are detailed in this manuscript. The model component is the NEMO platform driven at the surface by atmospheric conditions from the ECMWF ERA-Interim reanalysis. Ocean observations are assimilated by means of a reduced-order Kalman filter. Along track altimeter sea level anomaly, satellite sea surface temperature and sea ice concentration data and in situ temperature and salinity (T/S) vertical profiles are jointly assimilated. A 3D-VAR scheme provides an additional correction for the slowly-evolving large-scale biases in temperature and salinity.&lt;/p&gt;&lt;p&gt;The performance of the reanalysis is first addressed in the space of the assimilated observations and shows a clear dependency on the time-dependent in situ observation system, which is intrinsic to most reanalyses. The general assessment of GLORYS12V1 highlights a level of performance at the state-of-the-art and the reliability of the system to correctly capture the main expected climatic interannual variability signals for ocean and sea ice, the general circulation and the inter-basins exchanges. In terms of trends, GLORYS12V1 shows a higher than observed&amp;#160; warming trend together with a lower than observed global mean sea level rise.&lt;/p&gt;&lt;p&gt;Comparisons made with an experiment carried out on the same platform without assimilation show the benefit of data assimilation in controlling water masses properties and their low frequency variability. Examination of the deep signals below 2000 m depth shows that the reanalysis does not suffer from artificial signals even in the pre-Argo period.&lt;/p&gt;&lt;p&gt;Moreover, GLORYS12V1 represents particularly well the small-scale variability of surface dynamics and compares well with independent (non-assimilated) data. Comparisons made with a twin experiment carried out at &amp;#188;&amp;#176; resolution allows characterizing and quantifying the strengthened contribution of the 1/12&amp;#176; resolution onto the downscaled dynamics.&lt;/p&gt;&lt;p&gt;In conclusion, GLORYS12V1 provides a reliable physical ocean state for climate variability and supports applications such as seasonal forecasts. In addition, this reanalysis has strong assets to serve regional applications and should provide relevant physical conditions for applications such as marine biogeochemistry. In a near future, GLORYS12V1 will be maintained to be as close as possible to real time and could therefore provide a relevant reference statistical framework for many operational applications.&lt;/p&gt;

scholarly journals Stability of Halide Perovskite Solar Cell Devices: In Situ Observation of Oxygen Diffusion under Biasing

2018 ◽  
Vol 30 (39) ◽  
pp. 1802769 ◽  
Author(s):  
Hee Joon Jung ◽  
Daehan Kim ◽  
Sungkyu Kim ◽  
Joonsuk Park ◽  
Vinayak P. Dravid ◽  
...  
Keyword(s):  
Solar Cell ◽  
Oxygen Diffusion ◽  
Perovskite Solar Cell ◽  
In Situ Observation ◽  
Halide Perovskite

scholarly journals In-Situ Imaging of Molten High-Entropy Alloys Using Cold Neutrons

2019 ◽  
Vol 5 (2) ◽  
pp. 29 ◽  
Author(s):  
Nicholas Derimow ◽  
Louis Santodonato ◽  
Benjamin MacDonald ◽  
Bryan Le ◽  
Enrique Lavernia ◽  
...  
Keyword(s):  
Real Time ◽  
Liquid State ◽  
Single Phase ◽  
Neutron Imaging ◽  
Phase Changes ◽  
Vacuum Furnace ◽  
In Situ Observation ◽  
Complex Alloy ◽  
Phase Liquid

Real-time neutron imaging was utilized to produce a movie-like series of radiographs for in-situ observation of the remixing of liquid state immiscibility that occurs in equiatomic CoCrCu with the addition of Ni. A previous neutron imaging study demonstrated that liquid state immiscibility can be observed in-situ for the equiatomic CoCrCu alloy. In this follow-up study, equiatomic buttons of CoCrCu were placed alongside small Ni buttons inside an alumina crucible in a high-temperature vacuum furnace. The mass of the Ni buttons was specifically selected such that when melted in the same crucible as the CoCrCu buttons, the overall composition would become equiatomic CoCrCuNi. Neutron imaging was simultaneously carried out to capture 10 radiographs in 20 °C steps from 1000 °C to 1500 °C and back down to 1000 °C. This, in turn, produced a movie-like series of radiographs that allow for the observation of the buttons melting, the transition from immiscible to miscible as Ni is alloyed into the CoCrCu system, and solidification. This novel imaging process showed the phase-separated liquids remixing into a single-phase liquid when Ni dissolves into the melt, which makes this technique crucial for understanding the liquid state behavior of these complex alloy systems. As metals are not transparent to X-ray imaging techniques at this scale, neutron imaging of melting and solidification allows for the observation of liquid state phase changes in real time. Thermodynamic calculations of the isopleth for CoCrCuNix were carried out to compare the observed results to the predictions resulting from the current Thermo-Calc TCHEA3 thermodynamic database. The calculations show a very good agreement with the experimental results, as the calculations indicate that the CoCrCuNix alloy solidifies from a single-phase liquid when x ≥ 0.275, which is close to the nominal concentration of the CoCrCuNi alloy (x = 0.25). The neutron imaging shows that the solidification of CoCrCuNi results from a single-phase liquid. This is evident as no changes in the neutron attenuation were observed during the solidification of the CoCrCuNi alloy.

In-situ Observation of Silicon Epitaxy Breakdown with Real-Time Spectroscopic Ellipsometry

2004 ◽  
Vol 808 ◽  
Author(s):  
Charles W. Teplin ◽  
Dean H. Levi ◽  
Qi Wang ◽  
Eugene Iwaniczko ◽  
Kim M. Jones ◽  
...  
Keyword(s):  
Real Time ◽  
Spectroscopic Ellipsometry ◽  
Chemical Vapor ◽  
In Situ Observation ◽  
Epitaxial Silicon ◽  
Silicon Epitaxy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Hydrogenated Amorphous

ABSTRACTWe use in-situ real-time spectroscopic ellipsometry to observe the breakdown of silicon epitaxy during growth by hot-wire chemical vapor deposition (HWCVD) on Si (100) substrates. Representative data is presented for the two types of epitaxy breakdown that we have observed: 1) an immediate transition to hydrogenated amorphous silicon (a-Si:H), and 2) a slower transition where a-Si:H cones nucleate and grow until they eclipse further epitaxial growth. Simple models, consistent with transmission-electron and atomic-force micrographs, describe the evolution of both types of breakdown showing that real-time spectroscopic ellipsometry is a useful tool for monitoring the growth of epitaxial silicon.

In Situ Soldering Process Technique by Synchrotron X-Ray Imaging

2015 ◽  
Vol 754-755 ◽  
pp. 508-512
Author(s):  
M.A.A. Mohd Salleh ◽  
A. Sugiyama ◽  
Hideyuki Yasuda ◽  
Stuart D. McDonald ◽  
Kazuhiro Nogita
Keyword(s):  
Real Time ◽  
Void Formation ◽  
In Situ Observation ◽  
Cu Substrate ◽  
X Ray ◽  
Soldering Process ◽  
X Ray Imaging ◽  
Free Solder ◽  
First Time

This paper demonstrates the development of an experimental technique of in-situ observation for soldering of Sn-0.7wt%Cu lead-free solder on a Cu substrate which was achieved for the first time by synchrotron X-ray imaging. Reactions between liquid solder and Cu substrate during a soldering process were able to be recorded in real-time. Individual stages of the soldering process consisted of flux activation in removal of Cu oxide, solder melting and contact with the Cu substrate (wetting) and intermetallic compound (IMC) and void formation between the solder and Cu substrate. The technique development which includes experimental setup with calculated optimum beam energy in the range of 20 – 30 keV appears to result in a clear observation of real-time X-ray imaging of the soldering process. This technique provides a key method to understand the mechanism of formation of micro-electronic inter-connects for future electronic packaging applications.

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