Article
Multidisciplinary Sciences
Elizabeth Gutierrez-Meza, Ravyn Malatesta, Hongmo Li, Ilaria Bargigia, Ajay Ram Srimath Kandada, David A. Valverde-Chavez, Seong-Min Kim, Hao Li, Natalie Stingelin, Sergei Tretiak, Eric R. Bittner, Carlos Silva-Acuna
Summary: Frenkel excitons play a crucial role in the optical properties of organic semiconductors and are predicted to form bound exciton pairs. By using nonlinear coherent spectroscopy, bound biexcitons were identified in a model polymeric semiconductor, revealing correlations between excitons. Using a Frenkel exciton model, the binding energy of biexcitons was related to molecular parameters, offering insights into the electronic structure of polymeric semiconductors and other excitonic systems.
Article
Multidisciplinary Sciences
Zhenyue Wu, Shunning Li, Yasmin Mohamed Yousry, Walter P. D. Wong, Xinyun Wang, Teng Ma, Zhefeng Chen, Yan Shao, Weng Heng Liew, Kui Yao, Feng Pan, Kian Ping Loh
Summary: Researchers synthesized a two-dimensional organic-inorganic hybrid material with ferroelectric properties and achieved tunable ferroic orders through intercalation chemistry, providing new possibilities for engineering the ferroic and elastic properties of materials.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Christian Tantardini, Sebastian Kokott, Xavier Gonze, Sergey Levchenko, Wissam A. Saidi
Summary: In this study, the stability of small polarons in methylammonium lead iodide perovskite is investigated using density functional theory. It is found that the electron small polaron is unstable, while the hole small polaron is metastable at realistic operation temperatures. The hole polaron, with its close proximity to the conduction band and metastability, is expected to have a significant impact on charge-carrier recombination.
APPLIED MATERIALS TODAY
(2022)
Article
Chemistry, Physical
Mohamed Ben Bechir, Sami Znaidia
Summary: Lead-free halide double perovskites A(2)MM & PRIME;X-6 have been suggested as an alternative for lead-based halide perovskites in optoelectronic and photovoltaic applications. However, their photophysical properties have received relatively little attention. This research demonstrates the effects of small polaron formation and localization on carrier dynamics, as well as the primary conduction mechanism in Cs2CuSbCl6 perovskite. Ultrafast transient absorption spectroscopy reveals the formation of small polarons and their trapping of charge carriers due to a distorted lattice under photoexcitation. These findings contribute to a better understanding of Cs2CuSbCl6 perovskite and other antimony-based semiconductors.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Yaoyao Chen, Liwei Tang, Yi Liu, Tian Yang, Lina Hua, Xi Zeng, Junhua Luo, Zhihua Sun
Summary: In this study, a polar 2D hybrid perovskite with high linear absorption dichroism and self-powered photodetection capability was successfully synthesized. The findings suggest the potential application of 2D polar perovskite materials for self-powered photodetection.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Nikita I. Selivanov, Anna Yu. Samsonova, Ruslan Kevorkyants, Irina V. Krauklis, Yuri V. Chizhov, Boris V. Stroganov, Marios E. Triantafyllou-Rundell, Detlef W. Bahnemann, Constantinos C. Stoumpos, Alexei V. Emeline, Yury V. Kapitonov
Summary: The study introduces a new family of hybrid organic-inorganic 2D lead halides, reporting the first example of the hybrid organic-inorganic post-perovskite 3-cyanopyridinium lead tribromide (3cp)PbBr3. The new material exhibits unique structural connectivity and optical properties that show significant anisotropy within the inorganic layer plane.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Wenjun Rao, Mingli Li, Xiuli You, Zhenhong Wei, Mengxia Zhang, Lingyu Wang, Hu Cai
Summary: Research on a series of A(2)BX(4) type OIHP materials revealed that the position of double-substituted fluorine atoms on benzylamine has significant impacts on the phase transition behavior, and the organic template can lead to structures of different dimensions in the compounds.
INORGANIC CHEMISTRY
(2021)
Article
Engineering, Electrical & Electronic
Jun Zhao, Zhiqin Zheng, Wenli Liu, Xufang Tang, Dingfeng Jin, Xinxing Wang
Summary: This study prepared two-dimensional hybrid perovskite quantum dots with emission bands in the UV and blue regions, showing strong quantum confinement. Nonlinear optical scattering and absorption properties were observed in the 2D CPI QDs, demonstrating a high two-photon absorption coefficient. These findings reveal the potential of 2D CPI QDs in high optical limiting applications.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Multidisciplinary Sciences
Rui Cai, Indrajit Wadgaonkar, Jia Wei Melvin Lim, Stefano Dal Forno, David Giovanni, Minjun Feng, Senyun Ye, Marco Battiato, Tze Chien Sum
Summary: Through the study of zero-field exciton quantum beating and anomalous temperature dependence in cesium lead bromide perovskite nanocrystals (NCs) ensembles, we have uncovered the quantum transition and temperature dependence of exciton spin lifetimes. Quantum beating between exciton fine-structure splitting (FSS) levels allows for coherent ultrafast optical control of the excitonic degree of freedom. In addition, we have found that at temperatures close to room temperature, the depolarization of exciton spin is dominated by a motional narrowing process controlled by exciton multilevel coherence.
NATURE COMMUNICATIONS
(2023)
Review
Optics
Xitong Hong, Xingqiang Liu, Lei Liao, Xuming Zou
Summary: With the advancement of photonics and electronics, optoelectronic synapses are promising candidates to overcome the bottleneck of von Neumann architecture and revolutionize the field of visual bionics in the big data era. They are considered as the foundation for integrated artificial neural networks due to their advantageous properties like high bandwidth, low power consumption, and high-density integration. This review article focuses on the application prospects and current status of metal halide perovskite (MHP)-based optoelectronic synapses, discussing their ability to mimic biological synapses and analyzing the two essential structures, two-terminal optoelectronic synaptic memristors and three-terminal transistor synaptic phototransistors (SPTs), in terms of their features and operating mechanisms. Furthermore, the recent applications of optoelectronic synapses in neuromorphic systems, including neuromorphic computing, high-order learning behaviors, and neuromorphic vision systems, are summarized, outlining the potential opportunities and future development directions of these neuromorphic devices in the field of artificial intelligence (AI).
PHOTONICS RESEARCH
(2023)
Article
Chemistry, Physical
Zhoushilin Ruan, Shenlong Jiang, Qun Zhang, Yi Luo
Summary: This study presents a systematic demonstration of phononic fine-tuning in a two-dimensional lead-halide perovskite system through fluorination. The effects of fluorination on the structural distortion-induced phononic properties are investigated using ultrafast spectroscopy and temperature-dependent photoluminescence spectroscopy. The results reveal the subtle but profound impacts of fluorination on coherent phonon modes, phonon-phonon/electron-phonon interactions, and the hot-phonon bottleneck effect.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Rayan Chakraborty, Parikshit Kumar Rajput, Gokul M. Anilkumar, Shabnum Maqbool, Ranjan Das, Atikur Rahman, Pankaj Mandal, Angshuman Nag
Summary: Structural non-centrosymmetry in semiconducting organic-inorganic hybrid halide perovskites introduces functionalities like anomalous photovoltaics and nonlinear optical properties. By creating dissimilar non-covalent interactions at the organic-inorganic interface, Pb- and Bi-based two- and one-dimensional hybrid perovskites with polar non-centrosymmetric space groups can be designed. The non-centrosymmetry results in visible to infrared tunable nonlinear optical properties and anomalous photovoltaic effect in (MIPA)2PbI4 and (H3N-(CH2)3-NH(CH3)2)BiI5.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
I Gresits, Gy Thuroczy, O. Sagi, S. Kollarics, G. Csosz, B. G. Markus, N. M. Nemes, M. Garcia Hernandez, F. Simon
Summary: Magnetic nanoparticle based hyperthermia is a potential tool for treating malignant tumors, but a thorough understanding of the magnetic properties and complex magnetic susceptibility of samples is crucial. This study utilized non-resonant and resonant radiofrequency reflectometry to investigate the frequency-dependent magnetic susceptibility of an aqueous ferrite suspension, confirming the effectiveness of the approach.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
S. Lee, Wonjun Lee, W. Guohua, J. Ma, H. Zhou, M. Lee, E. S. Choi, K-Y Choi
Summary: The study of Ba2YWO6 reveals the presence of random magnetism, spin freezing phenomenon, and lack of long-range magnetic ordering, suggesting the proximate realization of a random spin-orbit dimer state in this material.
Article
Chemistry, Inorganic & Nuclear
Junzi Li, Zhihang Guo, Shuyu Xiao, Yudi Tu, Tingchao He, Wenjing Zhang
Summary: In this study, we synthesized core/shell hybrid perovskite nanocrystals with optimized optical stability and enhanced two-photon absorption, making them promising for application in nonlinear optoelectronic devices.
INORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Eimantas Duda, David Hall, Sergey Bagnich, Cameron L. Carpenter-Warren, Rishabh Saxena, Michael Y. Wong, David B. Cordes, Alexandra M. Z. Slawin, David Beljonne, Yoann Olivier, Eli Zysman-Colman, Anna Koehler
Summary: Thermally activated delayed fluorescence (TADF) relies on a small energy gap between the emissive singlet and the nonemissive triplet state, and this study demonstrates a method of fine-tuning the emitter photoluminescence properties by changes in the functionality of the donor dendrons.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Kalyani Patrikar, Urvashi Bothra, Valipe Ramgopal Rao, Dinesh Kabra
Summary: Coating electrodes with SAM to increase the work function of Cu surface does not necessarily correlate with trends in R-C and OFET drain current.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Dianming Sun, Eimantas Duda, Xiaochun Fan, Rishabh Saxena, Ming Zhang, Sergey Bagnich, Xiaohong Zhang, Anna Koehler, Eli Zysman-Colman
Summary: This work presents a solution to the challenge of developing high-performance solution-processed OLEDs by using highly efficient TADF dendrimers as emitters. By incorporating meta- and para-connected donor dendrons about a central triazine acceptor, the conflicting requirements of achieving a small Delta E-ST and a large oscillator strength are resolved. The solution-processed OLEDs exhibit excellent external quantum efficiency, current efficiency, and power efficiency, making them the most efficient host-free solution-processed OLEDs reported to date. Further optimization of the charge balance within the devices leads to improved efficiency rolloff at higher luminance.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Gopa Sardar, Atul Shukla, Evan G. Moore, Gangadhar Banappanavar, Shih-Chun Lo, Ebinazar B. Namdas, Dinesh Kabra
Summary: An aryl-polyfluorene polymer with high photoluminescence quantum yield and reduced excimer emission in its neat film is found to be suitable for laser applications. The low excitation energy and ASE threshold can be achieved by adjusting the aryl groups on the polymer chain.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Laxmi, Dinesh Kabra
Summary: The origin of broadband emission in two-dimensional layered halide perovskites is studied using temperature-dependent time-resolved photoluminescence (PL) spectra. The broad emission is observed due to the coupling of triplet states in the organic barrier and inorganic well.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Kashimul Hossain, Shivam Singh, Dinesh Kabra
Summary: Perovskite solar cells (PSCs) are the fastest-growing photovoltaic devices that have shown improved efficiency and stability through introducing multiple cations into the perovskite crystal structure. Through frequency-dependent photocurrent and dielectric measurements, this study compared PSCs based on triple monovalent cation CsFAMA with PSCs based on single monovalent cation MAPI. The results showed that CsFAMA-based PSCs had a lower dielectric relaxation time constant (tau(d)) compared to MAPI-based PSCs, which is attributed to a lower dielectric constant. The study also found a correlation between the relaxation process and the presence of monovalent cations, relative defect density, and thermal stability.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Balu Praveenkumar, Jan K. Zareba, Dinesh Kabra, Satishchandra Ogale, Ramamoorthy Boomishankar, Neetu Prajesh, Vijay Bhan Sharma, Shatruhan Singh Rajput, Chandan Kumar Singh, Prashant Dixit
Summary: In this study, a Zn(II)-based ferroelectric one-dimensional coordination network with high piezoelectric performance is reported and applied in piezoelectric nanogenerators. The structure and properties of the coordination polymer are revealed through experiments and calculations. The fabricated flexible composite devices show high power density output.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Editorial Material
Materials Science, Multidisciplinary
Zhuoying Chen, Dinesh Kabra, Yana Vaynzof
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Eimantas Duda, Subeesh Madayanad Suresh, David Hall, Sergey Bagnich, Rishabh Saxena, David B. Cordes, Alexandra M. Z. Slawin, David Beljonne, Yoann Olivier, Anna Koehler, Eli Zysman-Colman
Summary: This study introduces a molecular design that gradually increases the number of quasi-degenerate states to enhance the efficiency of thermally activated delayed fluorescence (TADF) using the oligomer approach. By selecting and arranging benzonitrile (BN) acceptors and amine donors, connected together via repetitive donor-acceptor units, the number of quasi-degenerate states is gradually increased. It is found that increasing the size of the oligomer enhances the rates of intersystem crossing and reverse intersystem crossing.
CHEMISTRY OF MATERIALS
(2023)
Article
Physics, Applied
Andrei Stankevych, Rishabh Saxena, Alexander Vakhnin, Falk May, Naomi Kinaret, Denis Andrienko, Jan Genoe, Heinz Baessler, Anna Koehler, Andrey Kadashchuk
Summary: The dynamics of charge carriers in disordered organic semiconductors is difficult to study spectroscopically. Thermally stimulated luminescence (TSL) and kinetic Monte Carlo (KMC) simulations were used to determine the density of states for charges in low-temperature conditions. The charge dynamics was found to be frustrated but could be overcome by using an infrared push pulse in TSL or allowing for long-range tunneling in KMC simulations. The results highlight the importance of considering spatial and energetic correlations for understanding charge behavior in organic semiconductors.
PHYSICAL REVIEW APPLIED
(2023)
Article
Energy & Fuels
Abhijit Singha, Ananta Paul, Sakshi Koul, Vikas Sharma, Sudhanshu Mallick, Kavaipatti Ramanathan Balasubramaniam, Dinesh Kabra
Summary: This study reports a four-terminal tandem device that integrates NIR-transparent perovskite solar cells with Si solar cells, addressing the stability gap issue. The optimized NIR-transparent perovskite solar cells, with a sputtered top transparent conducting electrode and oxide buffer layer, achieved high power conversion efficiencies of 17.1% and 16.0% for small and large areas, respectively. The integration of these cells with commercial monocrystalline PERC Si solar cells resulted in 4T tandem devices with a PCE exceeding 26%.
Article
Nanoscience & Nanotechnology
Kalyani Patrikar, V. Ramgopal Rao, Dinesh Kabra, Anirban Mondal
Summary: Contact resistance in organic devices is determined by the energy level mismatch and electronic coupling between injecting electrodes and organic semiconductors. Our study reveals the importance of energy levels and electronic coupling in governing charge transfer and contact resistance.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Nrita Gaur, Gangadhar S. Banappanavar, Dinesh Kabra
Summary: This paper presents a study on the stability of organic semiconductor-based optoelectronic devices. A comparative study was conducted on thermally activated delayed fluorescence (TADF) based organic light emitting diodes (OLEDs) with inorganic electron injection interlayers, lithium fluoride (LiF) and magnesium fluoride (MgF2). The OLEDs with LiF interlayer showed higher external quantum efficiency (EQE) of 19.7%, while the MgF2 interlayer-based OLEDs showed slightly lower average EQE of 19.1%. However, the MgF2-based OLEDs exhibited approximately seven-fold enhancement in stability compared to the LiF-based OLEDs.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Bhupesh Bhardwaj, Urvashi Bothra, Shivam Singh, Sophie Mills, T. J. Ronningen, Sanjay Krishna, Dinesh Kabra
Summary: The study explores the effects of active layer thickness and different interfacial layers on the suppression of leakage current in photodetectors. High-sensitivity perovskite photodetectors with a broadband response and low noise current are fabricated using a specific device structure. Optimal thickness of the active layer and use of a specific electron transport layer further enhance the overall performance of the photodetectors. Comparison with published reports demonstrates the advancements achieved in this study.
APPLIED PHYSICS REVIEWS
(2023)
Article
Materials Science, Multidisciplinary
Nakul Jain, Rishabh Saxena, Sumukh Vaidya, Wenchao Huang, Adam Welford, Christopher R. McNeill, Dinesh Kabra
Summary: This study investigates the changes in Quasi-Fermi-level (QFL) splitting in different alloy compositions of mixed semiconductor materials under light illumination, revealing the impact of light-induced charge carriers on open-circuit voltage (V-OC). Research on mixed semiconductor materials is important in the field of solar cells.
MATERIALS ADVANCES
(2022)