Article
Chemistry, Multidisciplinary
K. P. Mithun, Shalini Tripathi, Ahin Roy, N. Ravishankar, A. K. Sood
Summary: We investigated carrier relaxation dynamics in semiconducting tellurium nanowires using ultrafast time-resolved terahertz spectroscopy. The relaxation process was found to exhibit bi-exponential decay with two time scales depending on the amount of capping agent on the TeNWs surface. A coupled rate equation model was used to quantitatively understand the relaxation mechanisms and the observed temperature-dependent dynamics. Furthermore, the frequency-dependent THz photoconductivity was modeled using the Boltzmann transport equation, revealing the contributions of short range and Coulomb scattering rates in the relaxation process.
Article
Physics, Multidisciplinary
Yong Yang, Chuan He, Yuanyuan Huang, Lipeng Zhu, Yixuan Zhou, Xinlong Xu
Summary: In this study, the ultrafast carrier dynamics in layered MoS2 crystal was investigated using time-resolved terahertz spectroscopy. The real part of the THz photoconductivity decay time was found to be independent of pump power, while the imaginary part increased with pump power. The peak values of the complex photoconductivity showed saturation with pump power increase, indicating a many-body effect at high carrier concentration.
FRONTIERS IN PHYSICS
(2021)
Article
Optics
Jens Neu
Summary: Photoconductivity is crucial for assessing the potential of emerging materials for solar applications. While direct current measurements provide overall performance, terahertz spectroscopy offers contact-free and ultrafast measurements of photoconductivity, shedding light on carrier dynamics and scattering effects. This tutorial introduces main THz techniques, guides readers in extracting accurate photoconductivities, and discusses underlying physics.
Article
Chemistry, Multidisciplinary
Wenhao Zheng, Nicolas F. Zorn, Mischa Bonn, Jana Zaumseil, Hai Wang
Summary: This study investigated the microscopic and temperature-dependent charge transport properties of pristine and functionalized carbon nanotubes using ultrafast spectroscopy. The results showed that functionalization increased charge carrier scattering, leading to a decrease in intra-nanotube carrier mobility. Electrical measurements further distinguished the contributions of different factors to the overall charge transport properties.
Article
Optics
Yi-Chun Hung, Ta-Hsuan Chao, Pojen Yu, Shang-Hua Yang
Summary: This paper proposes a supervised THz deep learning computed tomography (THz DL-CT) framework based on time-domain information, which can restore superior THz tomographic images by extracting features from spatio-temporal THz signals. Compared with conventional methods, THz DL-CT delivers significantly better performance in terms of error and similarity index, and can be applied to reconstructing multi-material systems.
Article
Materials Science, Multidisciplinary
Ran Jing, Rocco A. Vitalone, Suheng Xu, Chiu Fan Bowen Lo, Zaiyao Fei, Elliott Runburg, Yinming Shao, Xinzhong Chen, Fabian Mooshammer, Alexander S. Mcleod, Mengkun Liu, Michael M. Fogler, David H. Cobden, Xiaodong Xu, D. N. Basov
Summary: In this study, the real-space features of the plasmonic response of few-layer WTe2 were visualized and evaluated using time-domain THz nanoimaging technique combined with scattering amplitude experiments.
Article
Physics, Applied
Monu Kinha, Malay Udeshi, Rahul Dagar, D. S. Rana
Summary: This study investigates the effect of oxygen annealing and epitaxial strain on the ultrafast carrier excitation and relaxation mechanism in charge-ordered manganite thin films, revealing a correlation between the relaxation time constants and the strain and oxygen content of the films.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Multidisciplinary Sciences
J. W. L. Lee, D. S. Tikhonov, P. Chopra, S. Maclot, A. L. Steber, S. Gruet, F. Allum, R. Boll, X. Cheng, S. Duesterer, B. Erk, D. Garg, L. He, D. Heathcote, M. Johny, M. M. Kazemi, H. Koeckert, J. Lahl, A. K. Lemmens, D. Loru, R. Mason, E. Mueller, T. Mullins, P. Olshin, C. Passow, J. Peschel, D. Ramm, D. Rompotis, N. Schirmel, S. Trippel, J. Wiese, F. Ziaee, S. Bari, M. Burt, J. Kuepper, A. M. Rijs, D. Rolles, S. Techert, P. Eng-Johnsson, M. Brouard, C. Vallance, B. Manschwetus, M. Schnell
Summary: Polycyclic aromatic hydrocarbons play a crucial role in interstellar chemistry, with high energy photons inducing ionization and fragmentation reactions. Through XUV-IR pump-probe experiments, the authors investigate the ultrafast photoinduced dynamics of fluorene, phenanthrene, and pyrene, shedding light on their preferred reaction pathways.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Condensed Matter
A. Bilde, K. Redeckas, A. Melninkaitis, M. Vengris, S. Guizard
Summary: By using femtosecond time-resolved absorption spectroscopy, researchers have found that the relaxation of excited carriers in alpha-Al2O3 is a non-exponential two-step process, involving trapping of initially free electron-hole pairs followed by recombination. This relaxation process is dependent on pump intensity and can be quantitatively reproduced by a numerical model accounting for initial electronic excitation and subsequent relaxation.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Nanoscience & Nanotechnology
Takehiro Tachizaki, Kan Hayashi, Yoshihiko Kanemitsu, Hideki Hirori
Summary: The combination of scanning tunneling microscopy and terahertz electromagnetic pulses has advanced significantly, providing atomic-level spatial resolution and femtosecond temporal resolution. It can capture real-time dynamics of electron diffusion and relaxation, and even control molecular motions instantaneously. This technology has great potential for materials research and development in ultrafast time-resolved THz scanning tunneling microscopy.
Article
Physics, Applied
Mohammad M. Taheri, Triet M. Truong, Siming Li, William N. Shafarman, Brian E. McCandless, Jason B. Baxter
Summary: Understanding the nature of recombination and its dependence on defects and interfaces is crucial for improving open-circuit voltage and power conversion efficiency in photovoltaic devices. The use of time-resolved terahertz spectroscopy and TRPL combined with numerical modeling allows for the quantification of carrier dynamics and recombination mechanisms, demonstrating the potential for developing thin-film PV technology with enhanced performance.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Wiebke Haselbach, Jeremy M. Kaminski, Laura N. Kloeters, Thomas J. J. Mueller, Oliver Weingart, Christel M. Marian, Peter Gilch, Barbara E. Nogueira de Faria
Summary: The emitters for TADF-based OLEDs need to have small S-1-T-1 energy gaps and fast ISC transitions. Vibronic mixing with higher excited states S-n and T-n can mediate these transitions. By using time-resolved NIR spectroscopy, it is demonstrated that the energetically located higher states can be found in a prototypical TADF emitter consisting of a triarylamine and a dicyanobenzene moiety (TAA-DCN).
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Optics
Simone Laterza, Antonio Caretta, Richa Bhardwaj, Roberto F. Lammini, Paolo Moras, Matteo Jugovac, Piu Rajak, Mahabul Islam, Regina Ciancio, Valentina Bonanni, Barbara Casarin, Alberto Simoncig, Marco Zangrando, Primoz Rebernik Ribic, Giuseppe Penco, Giovanni De Ninno, Luca Giannessi, Alexander Demidovich, Miltcho Danailov, Fulvio Parmigiani, Marco Malvestuto
Summary: In this study, the propagation characteristics of spin currents across metal-semiconductor interfaces were revealed using ultrafast time-resolved Kerr spectroscopy, providing experimental evidence for their existence and behavior.
Article
Chemistry, Multidisciplinary
Kaoru Ohta, Yuichi Hiramatsu, Mitsuharu Suzuki, Hiroko Yamada, Keisuke Tominaga
Summary: This study investigates local charge carrier dynamics in DPP-BP based bulk heterojunction films using optical pump-terahertz probe spectroscopy. The focus is on the impact of alkyl chain lengths of DPP on carrier dynamics, revealing similar dynamics between different BHJ films despite significant differences in power conversion efficiency. The origin of this similarity is discussed in terms of the high frequency response of photo-generated charge carriers.
Article
Optics
Gaofang Li, Xiaobo Nie, Yuao Liao, Wen Yin, Wei Zhou, Yanqing Gao, Nenghong Xia, Haoyang Cui
Summary: Ultrafast carrier dynamics and terahertz conductivity of intrinsic 6H-SiC are studied using optical-pump terahertz-probe spectroscopy. The results show that the increase in photogenerated carrier density affects the fast decay time and the evolution of complex conductivity, and the Drude-Smith model provides a better fit for the conductivity.
OPTICS COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Matthew Zervos, Epameinondas Leontidis, Eugenia Tanasa, Eugeniu Vasile, Andreas Othonos
JOURNAL OF PHYSICAL CHEMISTRY C
(2017)
Article
Nanoscience & Nanotechnology
Ignasi Burgues-Ceballos, Achilleas Savva, Efthymios Georgiou, Konstantinos Kapnisis, Paris Papagiorgis, Androniki Mousikou, Grigorios Itskos, Andreas Othonos, Stelios A. Choulis
Article
Chemistry, Physical
Matthew Zervos, Andreas Othonos, Eugenia Tanasa, Eugeniu Vasile
JOURNAL OF PHYSICAL CHEMISTRY C
(2018)
Article
Chemistry, Physical
Matthew Zervos, Andreas Othonos, Eugenia Tanasa, Eugeniu Vasile, Epameinondas Leontidis
JOURNAL OF PHYSICAL CHEMISTRY C
(2018)
Article
Chemistry, Physical
Matthew Zervos, Andreas Othonos, Eugenia Tanasa, Eugeniu Vasile
JOURNAL OF PHYSICAL CHEMISTRY C
(2019)
Article
Chemistry, Physical
Matthew Zervos, Andreas Othonos, Marios Sergides, Theodore Pavloudis, Joseph Kioseoglou
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Physics, Applied
Marios Sergides, Matthew Zervos, Andreas Othonos
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Chemistry, Physical
Matthew Zervos, Andreas Othonos, Theodore Pavloudis, Stefanos Giaremis, Joseph Kioseoglou, Kalliopi Mavridou, Maria Katsikini, Fani Pinakidou, Eleni C. Paloura
Summary: In this study, Cu3N layers were deposited and analyzed for their optical properties and the impact of surface oxidation on the band structure. It was found that oxygen can act as a shallow impurity dopant without creating midgap states, allowing for the modulation of the direct energy band gaps of the semiconductor.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Kyriacos Georgiou, Rahul Jayaprakash, Andreas Othonos, David G. Lidzey
Summary: This study investigates polariton-mediated energy transfer between coupled states in strong-coupled microcavities over mesoscopic distances. By separating thin-films of two J-aggregated molecular dyes with a spacer layer up to 2 micrometers thick, strong light-matter coupling and hybridisation between excitonic transitions were identified. The process of energy transfer through polaritons was found to be enhanced compared to non-cavity control structures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Nima Taghipour, Guy L. Whitworth, Andreas Othonos, Mariona Dalmases, Santanu Pradhan, Yongjie Wang, Gaurav Kumar, Gerasimos Konstantatos
Summary: A binary blend of CQDs and ZnO nanocrystals is used to passivate trap states in PbS-CQD gain medium, leading to improved Auger lifetime and suppression of trap-assisted Auger recombination. Integration of this binary blend with a DFB resonator has demonstrated stable single-mode lasing emission with low threshold and continuous operation of 5 hours under room temperature and ambient conditions.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Nima Taghipour, Mariona Dalmases, Guy L. Whitworth, Miguel Dosil, Andreas Othonos, Sotirios Christodoulou, Shanti Maria Liga, Gerasimos Konstantatos
Summary: This study utilizes PbS/PbSSe core/alloyed-shell colloidal quantum dots (CQDs) as a gain medium for infrared laser devices. The researchers achieved highly suppressed Auger recombination and lower amplified spontaneous emission (ASE) threshold by doping these engineered CQDs and successfully achieved near-infrared laser emission.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Kalliopi Mavridou, Maria Katsikini, Andreas Othonos, Nikoletta Florini, Philomela Komninou, Matthew Zervos
Summary: CuO nanowires are grown and converted into curly Cu3N nanowires by depositing Cu over the CuO and reacting with NH3:H-2. The obtained Cu3N nanowires exhibit good optical properties, but have short carrier lifetimes.
MATERIALS ADVANCES
(2022)
Article
Materials Science, Multidisciplinary
Nikolaos Kelaidis, Matthew Zervos, Nektarios N. Lathiotakis, Alexander Chroneos, Eugenia Tanasa, Eugeniu Vasile
Summary: PbO nanowires were synthesized via a self-catalysed, vapor-liquid-solid mechanism, with their morphology and structure varying under different temperatures and pressures. Tuning the parameters allows for reproducible control of the morphology, and the properties of the PbO/SnO2 heterojunction are crucial for energy conversion applications, such as solar cells and photocatalysis.
MATERIALS ADVANCES
(2022)
Article
Chemistry, Multidisciplinary
M. Zervos, N. Lathiotakis, N. Kelaidis, A. Othonos, E. Tanasa, E. Vasile
NANOSCALE ADVANCES
(2019)
Article
Chemistry, Physical
Andreas Charalampous, Matthew Zervos, Joseph Kioseoglou, Katerina Tsagaraki, Maria Androulidaki, George Konstantinidis, Eugenia Tanasa, Eugeniu Vasile
ACS APPLIED ENERGY MATERIALS
(2019)
