Article
Chemistry, Multidisciplinary
Yan Zhang, Haibing Zhang, Dongdong Chen, Cheng-Jun Sun, Yang Ren, Jianhui Jiang, Linjun Wang, Zheng Li, Xiaogang Peng
Summary: Zinc-blende CdS nanoplatelets with atomically flat {100} basal planes terminated by either Cd or S atoms were synthesized, showing different band gaps and optical properties. By precisely controlling the surface structure, it is possible to engineer the spatial distribution of excitons, opening up new possibilities for semiconductor nanocrystals.
Article
Chemistry, Multidisciplinary
Davit A. Baghdasaryan, Volodya A. Harutyunyan, David B. Hayrapetyan, Eduard M. Kazaryan, Sotirios Baskoutas, Hayk A. Sarkisyan
Summary: This paper theoretically investigates the exciton states and their influence on the optical absorption spectrum of CdSe and PbS nanoplatelets. The problem is discussed in different size quantization regimes, and the corresponding potential that describes the electron-hole interaction in this mode of space quantization is chosen. The study reveals single-particle energy spectra, wave functions, and the dependence of material parameters on the number of monolayers in the sample. The effect of dielectric coefficient mismatch and different electron-hole interaction potentials are also studied.
Article
Optics
Zhonglin Li, Yutian Yang, Xiaoxuan Fan, Shuai Guo, Zian Li, Yao Liang, Jie Jiang, Xiaoyuan Sun, Bo Zhong, Yingying Wang, Zhenhua Ni
Summary: This study discovers that 2D materials, such as MoS2 and GaSe, can be used as unique materials for high-resolution color printing, generating full color gamut and highly tunable colors. By adjusting the atomic thickness change in the Fabry-Perot cavity and exciton-induced additional absorption, the optical resonance peak can be tuned at the subnanometer level, achieving color resolution an order of magnitude higher than current technologies. Furthermore, color patterns fabricated using GaSe flakes exhibit high resolutions and can be selectively recognized by different visible light wavelengths.
LASER & PHOTONICS REVIEWS
(2022)
Article
Chemistry, Multidisciplinary
Elena Shornikova, Dmitri R. Yakovlev, Nikolay A. Gippius, Gang Qiang, Benoit Dubertret, Ali Hossain Khan, Alessio Di Giacomo, Iwan Moreels, Manfred Bayer
Summary: Colloidal semiconductor nanoplatelets exhibit strong quantum confinement for electrons and holes in one dimension, with significant increase in Coulomb interaction. The exciton binding energies are evaluated to be much higher compared to bulk CdSe, and comparable to monolayer-thick transition metal dichalcogenides.
Article
Chemistry, Multidisciplinary
Albert F. Vong, Shawn Irgen-Gioro, Yue Wu, Emily A. Weiss
Summary: Colloidal semiconductor nanoplatelets are scalable materials for optoelectronic applications and can be used for spin-to-photon transduction in quantum information networks. Negative trions are appealing emitters, but more preparation knowledge is needed to use them as single photon-emitting states. Through power-dependent time-resolved transient absorptions, it was shown that trions form via biexciton decay and not through collisional mechanisms typical for 2D materials.
Article
Chemistry, Physical
Igor M. Goncalves, Anusri Medda, Alyson J. A. Carvalho, Ceciilia L. A. V. Campos, Soubhik Ghosh, Anderson S. L. Gomes, Amitava Patra
Summary: The nonlinear optical response of CdSe and CdSe/CdS core/shell nanoplatelets in toluene suspension was studied using Z-scan and optical Kerr gate techniques. The Z-scan analysis yielded nonlinear coefficients of n(2) = 1.4 x 10(-16) cm(2)/W and n(2) = 1.3 x 10(-16) cm(2)/W for CdSe and CdSe/CdS NPLs, respectively. The dominant behavior was fifth-order nonlinear absorption, with alpha(4) = 4.0 x 10(-2) cm/GW for CdSe NPLs and alpha(4) = 9.0 x 10(-3) cm/GW for CdSe/CdS NPLs. The results from Z-scan and optical Kerr gate were in good agreement, and the response time from OKG was less than 1 ps for all materials. NLA was observed for CdSe and CdSe/CdS NPLs but not for toluene, indicating that the presence of NPLs reduces the threshold of absorptive nonlinearity. The electronic structure of the materials was discussed to explain the results.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Alireza Fali, Tianyi Zhang, Jason Patrick Terry, Ethan Kahn, Kazunori Fujisawa, Bernd Kabius, Sandhaya Koirala, Yassamin Ghafouri, Da Zhou, Wenshen Song, Li Yang, Mauricio Terrones, Yohannes Abate
Summary: The research demonstrates that the stability of 2D alloy regions and unique interface effects allow them to withstand extreme degradation effects over time, enabling stable 2D device engineering.
Review
Nanoscience & Nanotechnology
Youngbum Kim, Jeongyong Kim
Summary: Two-dimensional transition metal dichalcogenides (2D-TMDs) are atomically thin semiconductors with a direct bandgap, ideal for exciton-based optoelectronic devices. Near-field optical imaging is crucial for studying nanoscale features of exciton emissions and understanding the effects of local defects and carrier distributions.
Article
Chemistry, Multidisciplinary
Mahdi Samadi Khoshkhoo, Anatol Prudnikau, Mohammad Reza Chashmejahanbin, Ralf Helbig, Vladimir Lesnyak, Gianaurelio Cuniberti
Summary: This work focuses on the multicolor patterning of two-dimensional nanoplatelets via self-assembly and direct electron-beam lithography, demonstrating successful fabrication of fluorescent nanoarrays. The fabricated micro/nanoarrays provide an innovative platform for investigating biological interactions and Forster resonance energy transfer.
Article
Materials Science, Multidisciplinary
Michael Seitz, Marc Melendez, Nerea Alcazar-Cano, Daniel N. Congreve, Rafael Delgado-Buscalioni, Ferry Prins
Summary: Transient microscopy is crucial for understanding the dynamics of optical excited states in optoelectronic materials, providing a direct visualization of energy carrier movement. Long-acquisition time transient photoluminescence microscopy, combined with transient spectroscopy, reveals a distinct distribution of traps in 2D perovskites, explaining anomalous evolution of exciton distribution. These results highlight the value of transient microscopy as a complementary tool in semiconductor excited state dynamics characterization.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Arun Ashokan, Jiho Han, James A. Hutchison, Paul Mulvaney
Summary: We report an unexpected enhancement of photoluminescence (PL) in CdSe-based core/shell nanoplatelets (NPLs) upon electrochemical hole injection. Moderate hole doping densities induce an enhancement of more than 50% in PL intensity, accompanied by a narrowing and blue-shift of the PL spectrum. The hole-induced PL brightening in NPLs contrasts with the typical observation of PL quenching in CdSe-based quantum dots following hole injection. We propose that hole injection removes surface traps responsible for negative trions formation, thereby blocking nonradiative Auger processes. Continuous photoexcitation causes the enhanced PL intensity to decrease back to its initial level, indicating that photocharging is a key step in the loss of PL luminescence during normal aging. Modulation of the potential can be used for reversible enhancement or quenching of PL, enabling electro-optical switching.
Article
Chemistry, Multidisciplinary
Amal Ghribi, Rim Ben Aich, Kais Boujdaria, Thierry Barisien, Laurent Legrand, Maria Chamarro, Christophe Testelin
Summary: Lead halide perovskites are promising materials for optoelectronic devices due to their flexible synthesis and nanostructure shaping abilities. This study investigates excitonic band edge states and energy levels in colloidal inorganic lead halide nanoplatelets, focusing on the influence of dielectric effects in a thin quasi-2D system. A model incorporating band offset, dielectric confinements of Coulomb interaction reveals a full modelization of exciton fine structure in various phases with modified contributions from dielectric effects. The fine splitting structure, including dark and bright excitonic states, is discussed and compared to recent experimental results, highlighting the significance of confinement and dielectric contributions.
Article
Optics
Alexander M. Smirnov, Anastasiya D. Golinskaya, Bedil M. Saidzhonov, Roman B. Vasiliev, Vladimir N. Mantsevich, Vladimir S. Dneprovskii
Summary: The dynamics of resonantly excited excitons in CdSe/CdS nanoplatelets are determined by exciton-exciton interaction and phonon-induced cascade relaxation. The study also reveals the significance of exciton-exciton interaction in exciton dynamics, particularly in relation to the saturation of heavy-hole and light-hole exciton transitions. Additionally, the study experimentally investigates the lowest four band structure of CdSe/CdS nanoplatelets and the bleaching of higher energy transitions due to rapid cascade relaxation of electrons and holes.
JOURNAL OF LUMINESCENCE
(2021)
Article
Chemistry, Multidisciplinary
Alexander Schmitz, Federico Montanarella, L. Leander Schaberg, Mohamed Abdelbaky, Maksym Kovalenko, Gerd Bacher
Summary: This study investigates the luminescence and crystal structure of CsPbBr3 nanoplatelets using polarization-resolved spectroscopy at liquid helium temperature, revealing the existence of two distinct crystal configurations in the nanoplatelets. The absolute orientation of individual nanoplatelets on the substrate can be determined purely by optical means.
Article
Chemistry, Multidisciplinary
Zhuo Chen, Lvming Dong, Cheng Zhou, Binze Zhou, Zhi Zheng, Rong Chen, Jianfeng Zang
Summary: This study reports a moderate-temperature and atmospheric approach to synthesize highly luminescent Mn-doped CsPbCl3 nanoplatelets with only 4 monolayers. The nanoplatelets exhibit a high photoluminescence quantum yield and excellent stability for over 60 days at room temperature, enabling the first achievement of orange-red and warm white light-emitting diodes (LEDs) with prominent potential in flexible displays.
Article
Chemistry, Physical
Tsumugi Miyashita, Paulina Jaimes, Tianquan Lian, Ming Lee Tang, Zihao Xu
Summary: The study investigates the impact of ligands on photon upconversion and finds that long-chain ligands decrease the efficiency of energy transfer, while short-chain ligands enable direct energy transfer and enhance the upconversion quantum yield.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Tao Jin, Sheng He, Yifan Zhu, Eilaf Egap, Tianquan Lian
Summary: This study investigates the contribution of bright/dark states of quantum dots to triplet energy transfer. It is found that the bright states significantly contribute to the energy transfer, which is rationalized by bright state wave function components with the same electron/hole spin projections leading to nonzero energy transfer probability.
Article
Chemistry, Multidisciplinary
Shuang Liang, Sheng He, Mingyue Zhang, Yan Yan, Tao Jin, Tianquan Lian, Zhiqun Lin
Summary: This study demonstrates the efficient charge separation at the interface between metal halide perovskite quantum dots and conjugated polymers, which can be used as stable photocatalysts for photoinduced atom transfer radical polymerization. The use of CP-ligated perovskite quantum dots and amphiphilic starlike block copolymer nanoreactors allows for the production of stable and controllable nanomaterials with excellent structural stabilities and charge separation characteristics. These materials have potential applications in photodetectors, sensors, and LEDs, offering improved stabilities and tunable electronic band alignments.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Dhritiman Bhattacharyya, Pablo E. Videla, Joseph M. Palasz, Isaac Tangen, Jinhui Meng, Clifford P. Kubiak, Victor S. Batista, Tianquan Lian
Summary: Characterization of electrical double layers is important for understanding electrochemical processes. In this study, a spectroscopic method based on a Stark shift ruler was used to map the electric field strength across electrode/electrolyte interfaces. The results showed a distance-dependent electric field strength from the electrode surface and revealed significant solvent and electrolyte penetration within the self-assembled monolayer. The findings have implications for characterizing microenvironments surrounding molecular electrocatalysts and optimizing their functionality at specific distances from the electrode surface.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Sara T. Gebre, Laura M. Kiefer, Facheng Guo, Ke R. Yang, Christopher Miller, Yawei Liu, Clifford P. Kubiak, Victor S. Batista, Tianquan Lian
Summary: By immobilizing the soluble catalyst ReC0A on the surface of quantum dots (QDs), photoinduced CO2 reduction over a broad spectrum range can be achieved. It was found that the addition of triethylamine significantly enhances the electron transfer rate from Cd3P2 QDs to ReC0A, possibly by interacting with the QD surface, deprotonating the QD, and preferential solvation, resulting in a shift of the conduction band edge towards more negative potentials. The rate enhancement phenomenon was also observed in other QD-electron acceptor systems, providing mechanistic insights into hole scavenger-QD interactions in photoinduced interfacial electron transfer processes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
H. Ray Kelly, Pablo E. Videla, Clifford P. Kubiak, Tianquan Lian, Victor S. Batista
Summary: We investigated the effects of applied electric fields on the reactivity of two iridium(III) half-sandwich complexes bonded to gold electrodes. Our theoretical results showed that applied electric fields can precisely and linearly control the aqueous effective hydricities of these catalysts. The field-dependent shifts in the hydricities of Cp*Ir-bipyridine ([Ir-bpyH]+) and Cp*Ir-phenylpyridine (Ir-ppy-H) were found to be equivalent to a drastic change in substituent Hammett parameter without any chemical modification.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Daniel Chabeda, Dhritiman Bhattacharyya, H. Ray Kelly, Sara T. Gebre, Isaac Tangen, Clifford P. Kubiak, Victor S. Batista, Tianquan Lian
Summary: Covalent attachment of molecular catalysts to electrode surfaces is an attractive approach to develop robust catalytic materials. Selectivity and tunability of the resulting catalytic surface can be achieved by ligand design, making surface-attached CO2 catalysts of immense interest for zero carbon technologies. However, the functionality of heterogenized catalysts strongly depends on the nature of the electrode surface and the specific binding mode of the catalyst on the electrode surface.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Sheng He, Tao Jin, Anji Ni, Tianquan Lian
Summary: Two-dimensional lead halide perovskite nanoplatelets show promise for blue light emission due to strong quantum confinement. This study reveals the presence of two types of electron traps in 3 monolayer lead bromide perovskite nanoplatelets, with trapping lifetimes of 9.0 +/- 0.6 and 516 +/- 59 ps, respectively. These traps have minimal influence on charge transfer, but extend the half-lifetime of the charge-separated state from 2.1 +/- 0.1 to 68 +/- 3 ns after hole transfer. This research contributes to understanding carrier dynamics in 2D perovskite nanoplatelets and provides guidelines for improving their performance in optoelectronics and photocatalysis.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Sa Suo, Colton Sheehan, Fengyi Zhao, Langqiu Xiao, Zihao Xu, Jinhui Meng, Thomas E. Mallouk, Tianquan Lian
Summary: Metal-insulator-semiconductor (MIS) junctions are considered a promising architecture for water splitting and CO2 reduction reactions. However, it is challenging to directly measure the photovoltage at metal sites in MIS photoelectrodes. In this study, a new in situ spectroscopic approach using surface-enhanced Raman spectroscopy is developed to probe the quasi-Fermi level of metal catalyst sites in heterogeneous MIS photoelectrodes. The approach is successfully demonstrated on a CO2 reduction photocathode, showing selective probe of the photovoltage generated at the Si/SiO x /Ag junctions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Qiuyang Li, Adam Alfrey, Jiaqi Hu, Nathanial Lydick, Eunice Paik, Bin Liu, Haiping Sun, Yang Lu, Ruoyu Wang, Stephen Forrest, Hui Deng
Summary: A method based on 1-dodecanol encapsulation and gold-tape-assisted exfoliation is developed for the synthesis of large-area and high-quality transition metal dichalcogenide (TMD) monolayers. The encapsulated monolayers show uniform exciton energy, linewidth, and quantum yield over the whole area, and can be integrated with photonic crystal cavities to enhance light-matter coupling.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Yawei Liu, Wenxing Yang, Qiaoli Chen, Zhaoxiong Xie, Tianquan Lian
Summary: This study investigates the distance-dependence of charge separation and charge recombination times in a model system of Pt-tipped CdS quantum dots and CdS nanorods, and its impact on photo-driven H2 production. The study reveals that the quantum efficiency of H2 generation and the lifetimes of electron transfer and charge recombination are influenced by the length of the nanorods, providing insights into the mechanism of photocatalytic H2 production.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
William R. Lake, Jinhui Meng, Jahan M. Dawlaty, Tianquan Lian, Sharon Hammes-Schiffer
Summary: Interfacial electric fields have a crucial role in electrocatalysis, and the impact of electrode potential on the vibrational probe frequency can be influenced by the molecular structure and the orientation of the probe.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Boubacar Tanda Bonkano, Samuel Palato, Jannis Krumland, Sergey Kovalenko, Philipp Schwendke, Michele Guerrini, Qiuyang Li, Xiaoyang Zhu, Caterina Cocchi, Julia Staehler
Summary: The optical transitions of the monolayer WS2/terrylene hybrid were studied and a new transition was observed in the hybrid's spectrum. Experimental and computational analysis revealed fast hole transfer from WS2 to terrylene, indicating strong electronic coupling in this hybrid system.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Correction
Multidisciplinary Sciences
Qiuyang Li, Adam Alfrey, Jiaqi Hu, Nathanial Lydick, Eunice Paik, Bin Liu, Haiping Sun, Yang Lu, Ruoyu Wang, Stephen Forrest, Hui Deng
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Sara T. Gebre, Laura M. Kiefer, Facheng Guo, Ke R. Yang, Christopher Miller, Yawei Liu, Clifford P. Kubiak, Victor S. Batista, Tianquan Lian
Summary: In this study, the photoinduced CO2 reduction over a broad range of the solar spectrum was achieved by constructing ReC0A catalysts heterogenized on Cd3P2 quantum dots. The addition of triethylamine was found to enhance the electron transfer efficiency from Cd3P2 to ReC0A.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
