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.

scholarly journals Improved One- and Multiple-Photon Excited Photoluminescence from Cd2+-Doped CsPbBr3 Perovskite NCs

Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 151
Author(s):  
Ivan D. Skurlov ◽  
Wenxu Yin ◽  
Azat O. Ismagilov ◽  
Anton N. Tcypkin ◽  
Haohang Hua ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cross Sections ◽  
Nonlinear Optical ◽  
Metal Halide ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Trap States ◽  
Metal Halide Perovskite ◽  
Halide Perovskite ◽  
Optical Applications

Metal halide perovskite nanocrystals (NCs) attract much attention for light-emitting applications due to their exceptional optical properties. More recently, perovskite NCs have begun to be considered a promising material for nonlinear optical applications. Numerous strategies have recently been developed to improve the properties of metal halide perovskite NCs. Among them, B-site doping is one of the most promising ways to enhance their brightness and stability. However, there is a lack of study of the influence of B-site doping on the nonlinear optical properties of inorganic perovskite NCs. Here, we demonstrate that Cd2+ doping simultaneously improves both the linear (higher photoluminescence quantum yield, larger exciton binding energy, reduced trap states density, and faster radiative recombination) and nonlinear (higher two- and three-photon absorption cross-sections) optical properties of CsPbBr3 NCs. Cd2+ doping results in a two-photon absorption cross-section, reaching 2.6 × 106 Goeppert-Mayer (GM), which is among the highest reported for CsPbBr3 NCs.

In Situ TEM Analysis of Organic–Inorganic Metal-Halide Perovskite Solar Cells under Electrical Bias

Nano Letters ◽  
2016 ◽  
Vol 16 (11) ◽  
pp. 7013-7018 ◽  
Author(s):  
Quentin Jeangros ◽  
Martial Duchamp ◽  
Jérémie Werner ◽  
Maximilian Kruth ◽  
Rafal E. Dunin-Borkowski ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Metal Halide ◽  
In Situ Tem ◽  
Tem Analysis ◽  
Metal Halide Perovskite ◽  
Halide Perovskite ◽  
Electrical Bias

scholarly journals High-energy resolution X-ray absorption and emission spectroscopy reveals insight into unique selectivity of La-based nanoparticles for CO2

2015 ◽  
Vol 112 (52) ◽  
pp. 15803-15808 ◽  
Author(s):  
Ofer Hirsch ◽  
Kristina O. Kvashnina ◽  
Li Luo ◽  
Martin J. Süess ◽  
Pieter Glatzel ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Emission Spectroscopy ◽  
High Energy ◽  
Unit Cell ◽  
High Energy Resolution ◽  
Electron Configuration ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

The lanthanum-based materials, due to their layered structure and f-electron configuration, are relevant for electrochemical application. Particularly, La2O2CO3 shows a prominent chemoresistive response to CO2. However, surprisingly less is known about its atomic and electronic structure and electrochemically significant sites and therefore, its structure–functions relationships have yet to be established. Here we determine the position of the different constituents within the unit cell of monoclinic La2O2CO3 and use this information to interpret in situ high-energy resolution fluorescence-detected (HERFD) X-ray absorption near-edge structure (XANES) and valence-to-core X-ray emission spectroscopy (vtc XES). Compared with La(OH)3 or previously known hexagonal La2O2CO3 structures, La in the monoclinic unit cell has a much lower number of neighboring oxygen atoms, which is manifested in the whiteline broadening in XANES spectra. Such a superior sensitivity to subtle changes is given by HERFD method, which is essential for in situ studying of the interaction with CO2. Here, we study La2O2CO3-based sensors in real operando conditions at 250 °C in the presence of oxygen and water vapors. We identify that the distribution of unoccupied La d-states and occupied O p- and La d-states changes during CO2 chemoresistive sensing of La2O2CO3. The correlation between these spectroscopic findings with electrical resistance measurements leads to a more comprehensive understanding of the selective adsorption at La site and may enable the design of new materials for CO2 electrochemical applications.

scholarly journals Response to Comment on “Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells”

Science ◽  
2021 ◽  
Vol 371 (6532) ◽  
pp. eabd8598
Author(s):  
Zhenyi Ni ◽  
Shuang Xu ◽  
Jinsong Huang
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Differential Capacitance ◽  
Drive Level ◽  
Trap Density ◽  
Trap States ◽  
Doping Analysis ◽  
Metal Halide Perovskite ◽  
Diffusion Capacitance ◽  
Halide Perovskite

Ravishankar et al. claimed that drive-level capacitance profiling (DLCP) cannot resolve trap density in perovskites of given thickness. We point out that the trap densities derived by DLCP are from the differential capacitance at different frequencies; thus, the background charges caused by diffusion and geometry capacitance have been subtracted. Even for the nondifferential doping analysis, the contribution from diffusion capacitance is negligible and that from geometry capacitance is excluded.

In-Situ Measurement of Artificial Nuclides in Seabed Sediments Based on Monte Carlo Simulations and an Underwater HPGe Detector

2019 ◽  
Vol 53 (3) ◽  
pp. 16-22
Author(s):  
Jinzhao Zhang ◽  
Hongzhi Li ◽  
Xianguo Tuo
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Energy Resolution ◽  
Hpge Detector ◽  
High Energy ◽  
In Situ Measurement ◽  
Energy Calibration ◽  
High Energy Resolution ◽  
Seabed Sediments

AbstractIn-situ measurement of marine sediment radioactivity does not destroy the stratification of radionuclides in the sediment. We develop a novel seabed sediment radioactive measurement technique using a High Purity Germanium (HPGe) detector. The overall measurement system is designed, and the detector energy calibration is performed. The efficiency is calculated based on Monte Carlo simulations using the MCNP5 code. We compared the efficiency and energy resolution with the NaI(Tl) detection through experiments. NaI(Tl) detection is incapable of identifying the 137Cs artificial nuclides in seabed sediments due to the energy resolution limit. Hence, underwater HPGe detection is utilized due to its high energy resolution, which enables the detection of artificial nuclides 137Cs. The proposed method is of great significance in evaluating marine radioactive pollution.

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

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
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