Article
Chemistry, Multidisciplinary
Partha Maity, Noor A. Merdad, Jehad K. El-Demellawi, Luis Gutierrez-Arzaluz, Zhixiong Liu, Rounak Naphade, Husam N. Alshareef, Osman M. Bakr, Omar F. Mohammed
Summary: In this study, the charge carrier dynamics at the interface between CsPbBr3 multiple quantum wells (MQWs) and TiO2 and Spiro-OMeTAD were investigated, and it was found that the charge carrier extraction occurred through a quantum tunneling effect. The impact of the barrier-thickness-dependent quantum tunneling effect on the photoelectric behavior of the synthesized QW photodetector devices was also studied.
Article
Chemistry, Physical
Sreejith Kaniyankandy
Summary: The study investigates the hindered hot carrier cooling in lead halide perovskites using femtosecond transient absorption technique. Under low carrier densities, dynamics are governed by electron-hole radiative recombination, while under higher carrier densities, additional lifetime components contribute. The role of Auger heating and LO phonon filling was confirmed through fitting energy loss rate vs carrier temperature with different cooling models, suggesting potential for extracting hot carriers before cooling in HC photovoltaics.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Physical
Goutam Ghosh, Kritiman Marjit, Srijon Ghosh, Amitava Patra
Summary: We investigate the fast hot-carrier (HC) relaxation and Auger recombination (AR) rates in hexapod CsPbBr3 NCs using ultrafast transient absorption (TA) spectroscopy. Our results show that hexapod CsPbBr3 has a prolonged HC cooling time and bi-exciton lifetime compared to cubic CsPbBr3. By employing the electron-phonon coupling model, we confirm the slower HC relaxation rate in hexapod CsPbBr3, suggesting a delayed decay of longitudinal optical (LO) phonons. We demonstrate that delocalization of charge carriers in shallow trap states leads to reduced overlap of electron and hole wave functions and suppresses the bi-exciton AR rate.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Gurpreet Kaur, Ramchandra Saha, K. Justice Babu, Ayushi Shukla, Hirendra N. Ghosh
Summary: There is a significant interest in heterojunction devices based on perovskite and other semiconducting materials within the global scientific community, with the CsPbBr3 and PbS system showing potential for phototransistor applications. By using femtosecond broadband transient absorption spectroscopy, the investigation into carrier transfer mechanisms in the CsPbBr3/PbS architecture revealed bidirectional or unidirectional carrier transfer behaviors depending on the density energy states of the carriers.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Peng Zeng, Xinjian Ren, Linfeng Wei, Haifeng Zhao, Xiaochun Liu, Xinyang Zhang, Yanmin Xu, Lihe Yan, Klaus Boldt, Trevor A. Smith, Mingzhen Liu
Summary: In this study, the cooling rate of hot carriers in CsPbBr3 nanocrystals was found to be three times lower when capped with a cross-linked polysiloxane shell compared to single alkyl-chain oleylamine ligands. Measurements using cryogenic photoluminescence spectroscopy revealed the strength of carrier-phonon coupling in the two samples. The effect of organic ligands on the coupling process was explained using a damped oscillation model, which also accounted for the observed linear temperature-dependence.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Kwang Jae Lee, Noor A. Merdad, Partha Maity, Jehad K. El-Demellawi, Zhixiong Lui, Lutfan Sinatra, Ayan A. Zhumekenov, Mohamed N. Hedhili, Jung-Wook Min, Jung-Hong Min, Luis Gutierrez-Arzaluz, Dalaver H. Anjum, Nini Wei, Boon S. Ooi, Husam N. Alshareef, Omar F. Mohammed, Osman M. Bakr
Summary: This study introduces artificial perovskite-based MQWs with different band offset alignments, showing the disparity in charge carrier dynamics between type-I and type-II MQWs through transient absorption spectroscopy. Photodiodes of different types of artificial MQWs exhibit different carrier behaviors and photoresponse characteristics, with type-II MQW photodiodes showing a more than tenfold increase in rectification ratio compared to bulk perovskite devices. These findings open new opportunities for producing halide-perovskite-based quantum devices through bandgap engineering.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Dipti Jasrasaria, Eran Rabani
Summary: Nonradiative processes control the efficiencies of semiconductor nanocrystal-based devices, and hot exciton cooling is a central process in which highly excited electron/hole pairs relax to form band-edge excitons through nonradiative means. However, the timescale and mechanism of cooling in nanocrystals are not well understood due to quantum confinement effects. Experimental measurements of the cooling timescale range six orders of magnitude.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Shu Hu, Yongtao Huang, Yang Zhang, Pingyuan Yan, Heng Li, ChuanXiang Sheng
Summary: A significantly slow hot-carrier-cooling phenomenon is observed in a multiphase quasi two-dimensional perovskite film, resulting in a blue-shift and multi-peak emission in the photoluminescence spectra. Furthermore, hot-carrier emission from small n materials is observed using a continuous wave laser, leading to an abnormal enhancement of the open-circuit voltage.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Herath P. Piyathilaka, Rishmali Sooriyagoda, Hamidreza Esmaielpour, Vincent R. Whiteside, Tetsuya D. Mishima, Michael B. Santos, Ian R. Sellers, Alan D. Bristow
Summary: The research focuses on the photoexcited carrier dynamics in InAs/AlAs0.16Sb0.84 multiple-quantum well sample, revealing significant influences of excitation photon energy and lattice temperature on transient terahertz absorption. With sufficient excess-photon energy, the metastable state transitions to long-lived states. As temperature increases, the long-lived decay times also increase.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
Li Chen, Yijun Dai, Liang Li, Jiean Jiang, Houqiang Xu, Kuang-hui Li, Tien Khee Ng, Mei Cui, Wei Guo, Haiding Sun, Jichun Ye
Summary: This study reports a significantly boosted defect-insensitive ultraviolet emission from InGaN/GaN multiple quantum wells grown on patterned AlN nucleation layer compared to samples grown on uniform nucleation layer. Carrier localization is clearly illustrated for MQWs grown on patterned AlN NL as evidenced by temperature-dependent photoluminescence characterization. The underlying mechanism for the carrier localization is demonstrated to be correlated with partial relaxation of compressive strains inside epitaxial thin films.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Multidisciplinary Sciences
Claudiu M. Iaru, Annalisa Brodu, Niels J. J. van Hoof, Stan E. T. ter Huurne, Jonathan Buhot, Federico Montanarella, Sophia Buhbut, Peter C. M. Christianen, Daniel Vanmaekelbergh, Celso de Mello Donega, Jaime Gomez Rivas, Paul M. Koenraad, Andrei Yu Silov
Summary: By investigating the phonon spectrum, a dominant phonon mode in CsPbBr3 responsible for electron-phonon scattering was identified, and it was found that the strength of the Frohlich interaction is significantly higher due to carrier localization in colloidal perovskite nanocrystals.
NATURE COMMUNICATIONS
(2021)
Article
Optics
Wenyan Wang, Ning Sui, Zhihui Kang, Qiang Zhou, Li Li, Xiaochun Chi, Hanzhuang Zhang, Xing He, Bing Zhao, Yinghui Wang
Summary: This study investigates the hot carrier dynamics in the C excitonic state of monolayer WS2 using transient absorption spectroscopy. The hot carrier cooling lifetime increases with the absorbed photon flux, exhibiting a distinct spectral feature compared to normal carriers. The results provide insights into the behavior of hot carriers in 2D TMDCs and offer guidance for designing high-performance TMDC-based electronic devices.
Article
Nanoscience & Nanotechnology
Yoel Negrin-Montecelo, Adbelrhaman Hamdeldein Ahmed Geneidy, Alexander O. Govorov, Ramon A. Alvarez-Puebla, Lucas V. Besteiro, Miguel A. Correa-Duarte
Summary: Photocatalysis is a promising alternative energy technology that converts solar energy into chemical products. This study explores the use of plasmonic materials to sensitize traditional semiconductor photocatalysts. Using CdS quantum dots as a bridging system, energy from Au nanostructures is transferred to TiO2 nanoparticles, resulting in significantly accelerated reactions. The study highlights the importance of the morphology of the Au nanoparticles in their photosensitizing capabilities.
Article
Chemistry, Multidisciplinary
Chih-Wei Wang, Xiaohan Liu, Tian Qiao, Mohit Khurana, Alexey V. Akimo, Dong Hee Son
Summary: This study identifies Mn-doped CsPbBr3 nanocrystals as an excellent platform for hot electron upconversion, benefiting from the structural diversity of metal halide perovskites. Two-dimensional Mn-doped CsPbBr3 nanoplatelets are particularly advantageous in the upconversion process due to the strong exciton-dopant interaction, and evidence for hot electron upconversion via long-lived dark excitons is observed.
Article
Chemistry, Multidisciplinary
Goutam Ghosh, Kritiman Marjit, Srijon Ghosh, Debarati Ghosh, Amitava Patra
Summary: This study investigates the hot-electron transfer dynamics in hybrid CsPbBr3/rGO-Ph-SH materials and reveals that hot-electron transfer is three times faster than band-edge electron transfer, with a maximum transfer efficiency of 43%.
Article
Chemistry, Physical
Khulud Almasabi, Xiaopeng Zheng, Bekir Turedi, Abdullah Y. Alsalloum, Muhammad Naufal Lintangpradipto, Jun Yin, Luis Gutierrez-Arzaluz, Konstantinos Kotsovos, Aqil Jamal, Issam Gereige, Omar F. Mohammed, Osman M. Bakr
Summary: The difficulty of growing perovskite single crystals suitable for efficient photovoltaic devices has been a challenge. Here, we report the growth of mixed-cation FA0.6MA0.4PbI3 perovskite single crystals on a hydrophilic self-assembled monolayer. The single crystals exhibit enhanced stability and power conversion efficiencies up to 23.1%, setting a new benchmark for perovskite solar cells.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Zhiming Zhao, Jun Yin, Jian Yin, Xianrong Guo, Yongjiu Lei, Zhengnan Tian, Yunpei Zhu, Omar F. Mohammed, Husam N. Alshareef
Summary: Sustainable battery development is aiming at using aqueous electrolytes to store renewable energy on a large scale. However, the hydrogen evolution reaction (HER) on the anode of aqueous batteries poses a challenge. In this study, by regulating mass transfer kinetics and blocking proton conduction with N-methyl-2-pyrrolidone (NMP), the HER in aqueous batteries is mitigated and stable full-cell batteries are achieved with high Coulombic efficiency.
ENERGY STORAGE MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Saidkhodzha Nematulloev, Arunachalam Sagadevan, Badriah Alamer, Aleksander Shkurenko, Renwu Huang, Jun Yin, Chunwei Dong, Peng Yuan, Khursand E. Yorov, Azimet A. Karluk, Wasim J. Mir, Bashir E. Hasanov, Mohamed Nejib Hedhili, Naveen M. Halappa, Mohamed Eddaoudi, Omar F. Mohammed, Magnus Rueping, Osman M. Bakr
Summary: This study reports the synthesis of atomically precise copper hydride nanoclusters with a controlled defect, which were demonstrated to be highly selective catalysts for C-C cross-couplings. The work highlights the potential of defective nanoclusters as model systems for investigating individual defects, correlating defects with physicochemical properties, and rationally designing new nanoparticle catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Optics
Kostiantyn Sakhatskyi, Bekir Turedi, Gebhard J. Matt, Erfu Wu, Anastasiia Sakhatska, Vitalii Bartosh, Muhammad Naufal Lintangpradipto, Rounak Naphade, Ivan Shorubalko, Omar F. Mohammed, Sergii Yakunin, Osman M. Bakr, Maksym V. Kovalenko
Summary: We demonstrate single-photon counting and long-term stability of perovskite X-ray detectors in the photovoltaic mode, using thick and uniform methylammonium lead iodide single-crystal films (up to 300 μm) and solution directly grown on hole-transporting electrodes. These findings pave the path for the implementation of hybrid perovskites in low-cost, low-dose commercial detector arrays for X-ray imaging with single-photon sensitivity.
Article
Optics
Sultan Alshaibani, Omar Alkhazragi, Islam Ashry, Chun Hong Kang, Mohammed Sait, Tien Khee Ng, Osman M. Bakr, Boon S. Ooi
Summary: All-inorganic CsPbBr3 nanocrystals are used to extend the field-of-view (FOV) of optical concentrators to 60 degrees, reducing the requirements of pointing, acquisition, and tracking (PAT) in optical wireless communication links. The CsPbBr3 nanocrystals convert transmitted UV light into green light that matches the peak absorption of Si-based detectors, allowing stable communication over the wide FOV.
Article
Physics, Multidisciplinary
Artem G. Volosniev, Abhishek Shiva Kumar, Dusan Lorenc, Younes Ashourishokri, Ayan A. Zhumekenov, Osman M. Bakr, Mikhail Lemeshko, Zhanybek Alpichshev
Summary: Lead halide perovskites have remarkable optoelectronic properties. To understand their origin, the interactions between electromagnetic fields and these systems are studied. The Faraday effect and complex refractive index in a paradigmatic perovskite CH3NH3PbBr3 are investigated, and it is found that the minimal coupling of electromagnetic fields to the k center dot p Hamiltonian alone is insufficient to explain the data. A relevant atomic-level coupling between electromagnetic fields and the spin degree of freedom is demonstrated to provide a quantitative description. The Faraday effect in lead halide perovskites is dominated by Zeeman splitting and has a significant beyond-Becquerel contribution.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Zhiming Zhao, Binbin Nian, Yongjiu Lei, Yizhou Wang, Lin Shi, Jian Yin, Omar F. Mohammed, Husam N. Alshareef
Summary: Nanoscale Zn2+ channels have been successfully engineered in a plastic-crystal electrolyte, enabling fast Zn2+ solid-state transport and high conductivity. This work offers new perspectives for developing super multivalent ion conductors.
ADVANCED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Noor A. Merdad, Yue Wang, Omar Alkhazragi, Zyad O. F. Mohammed, Partha Maity, Luis Gutierrez-Arzaluz, Haoze Yang, Rounak Naphade, Chun Hong Kang, Tien Khee Ng, Osman M. Bakr, Boon S. Ooi
Summary: In this study, the authors fabricated cesium lead bromide (CsPbBr3) thin films of varying thicknesses and investigated their visible-light communication (VLC) performance. Thicker films were found to have a more homogeneous surface and fewer surface trap states than thinner films. The 20-nm-thick CsPbBr3 film exhibited the best performance with a -3-dB bandwidth of 30.7 MHz and a net data rate of 330 Mb/s, making it suitable for high-power, high-speed, and large-area transmission and detection of visible-light signals.
Article
Engineering, Environmental
Feng Shui, Qiong Lei, Xinglong Dong, Tingting Pan, Zhiyuan Zhang, Jinli Li, Mao Yi, Laiyu Zhang, Xiongli Liu, Zifeng You, Shiqi Yang, Rufeng Yang, Hongbo Zhang, Jixin Li, Zhan Shi, Jun Yin, Baiyan Li, Xian-He Bu
Summary: By manipulating two types of adsorption sites, ionic binding sites and Lewis binding sites, a highly efficient I2 nanotrap was constructed, demonstrating a record-high iodine uptake capacity for COFs. This work opens up new possibilities for the rational design of COF materials for efficient iodine capture and related applications.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Ruiqian Li, Yifan Zhou, Xuanyu Zhang, Jiawei Lin, Jian Chen, Congcong Chen, Xin Pan, Pan Wang, Rui Chen, Jun Yin, Lingling Mao
Summary: A new family of double-perovskite-derived halides, (Mor)2ABX6, with unique one-dimensional structures, has been reported by introducing an organic cationic ligand morpholine. Optoelectronic performance can be enhanced by doping strategies.
CHEMISTRY OF MATERIALS
(2023)
Article
Multidisciplinary Sciences
Yongjiu Lei, Wenli Zhao, Jun Yin, Yinchang Ma, Zhiming Zhao, Jian Yin, Yusuf Khan, Mohamed Nejib Hedhili, Long Chen, Qingxiao Wang, Youyou Yuan, Xixiang Zhang, Osman M. Bakr, Omar F. Mohammed, Husam N. Alshareef
Summary: The three-proton intercalation mechanism in α-molybdenum trioxide is uncovered using a specially designed electrolyte, leading to an improved specific discharge capacity. Experimental and theoretical evidence verifies the semiconductor-to-metal transition behavior and the expansion of lattice interlayers after proton trapping. Fracture behavior is observed during the proton intercalation process, creating diffusion channels for hydronium ions. Additionally, an additional redox behavior at low potential is observed, contributing to an enhanced specific discharge capacity of α-molybdenum trioxide.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Yang Zhou, Tengyue He, Peng Yuan, Jun Yin, Shulin Chen, Luis Gutierrez-Arzaluz, Lijie Wang, Osman M. Bakr, Omar F. Mohammed
Summary: Copper halide clusters have garnered attention in light-emitting diodes and optical sensors due to their unique physicochemical properties and diverse chemical structures. Recently, they have also been explored as promising scintillation materials because of their large absorption cross section for X-ray radiation. However, research on copper halide cluster scintillators is still in its early stages and their performance lags behind that of perovskite and its related metal halide structures.
ACS MATERIALS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jian-Xin Wang, Indranil Dutta, Jun Yin, Tengyue He, Luis Gutierrez-Arzaluz, Osman M. Bakr, Mohamed Eddaoudi, Kuo-Wei Huang, Omar F. Mohammed
Summary: In this study, a highly efficient and reabsorption-free transparent X-ray imaging scintillator was fabricated by utilizing an efficient triplet-triplet energy transfer strategy between TADF-Br and Ir-OMC. The experiments and calculations showed that efficient energy transfer from TADF-Br to Ir-OMC can be achieved, leading to enhanced triplet-state radioluminescence upon X-ray irradiation. The fabricated scintillator achieved a high X-ray imaging resolution of 19.8 lp mm -1 .
Article
Engineering, Chemical
Nawader Alqadhi, Mohamed H. Abdellah, Sarvarkhodzha Nematulloev, Omar F. Mohammed, Mahmoud A. Abdulhamid, Gyorgy Szekely
Summary: Polymer engineering can improve the properties and performance of membranes. In this study, two customized PEEKs were synthesized and green membrane preparation methods were used. The effects of polymer structure, green solvent, and crosslinking on membrane performance were investigated, as well as the molecular interaction between organic solvents and PEEKs. The membranes showed high permeance and long-term stability in acetone, making them suitable for active pharmaceutical ingredient purification.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)