Article
Chemistry, Multidisciplinary
Yifan Bo, Yuxuan Hou, Dominik Thiel, Renee Weiss, Timothy Clark, Michael J. Ferguson, Rik R. Tykwinski, Dirk M. Guldi
Summary: This study designs two tetracene dimers with different linking modes, and characterizes the interplay between intramolecular singlet fission (intra-SF) and intramolecular triplet-triplet annihilation up-conversion (intra-TTA-UC) through steady-state and time-resolved absorption and fluorescence spectroscopy. By using Pd-phthalocyanine as a sensitizer, intra-TTA-UC is achieved in the two dimers via indirect photoexcitation in the near-infrared part of the solar spectrum. Temperature-dependent measurements reveal the impact of thermal effects on intra-SF and intra-TTA-UC in different dimers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Joseph K. Gallaher, Katherine M. Wright, Laszlo Frazer, Rowan W. MacQueen, Maxwell J. Crossley, Felix N. Castellano, Timothy W. Schmidt
Summary: The performance of a perylene monoimide annihilator in a photochemical upconversion composition shows promising results, outperforming the commonly used rubrene annihilator at low excitation intensity. However, its performance is hindered under strong excitation due to a low annihilation singlet yield. The upconversion composition utilizing perylene monoimide is capable of utilizing more than 12% of the generated triplet states to generate emissive, excited singlet states under one sun illumination, potentially enhancing the energy conversion efficiency of high band gap solar cells.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Katsuyuki Shizu, Chihaya Adachi, Hironori Kaji
Summary: Singlet fission materials have the potential to overcome traditional efficiency limits of OLEDs, with 55BT showing efficient SF in a locally excited singlet state. Its covalent bonding of tetracene units makes it a promising triplet sensitizer for near-infrared OLEDs, compared to other SF systems like the tetracene dimer.
Article
Chemistry, Multidisciplinary
Guiying He, Kaia R. Parenti, Luis M. Campos, Matthew Y. Sfeir
Summary: Singlet fission refers to the process of generating two triplet excitons from a single absorbed photon. However, there are ambiguities in this definition due to the complexity of double triplet states and their interconversion processes. Traditional models depict singlet fission as a sequential two-step conversion, but they overlook the possibility of directly harvesting energy from coupled triplet pairs. This study demonstrates the direct extraction of individual triplet excitons from bound triplet pairs and quantifies the energy harvesting efficiency using unique spectral and kinetic features.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Jiayi Song, Yunxia Guan, Cheng Wang, Xi Bao, Wanjiao Li, Lijia Chen, Lianbin Niu
Summary: The effect of varying thicknesses of TmPyPb on the electroluminescence performance of OLEDs was investigated by fabricating devices and measuring their magneto-electroluminescence. The study found that as the thickness of TmPyPb increases, the maximum luminance of the devices decreases due to an increase in the triplet-charge annihilation process. Additionally, the thickness of TmPyPb affects the luminance efficiency of the devices, with a decrease at first and then an enhancement.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Jiayi Song, Yunxia Guan, Cheng Wang, Xi Bao, Wanjiao Li, Lijia Chen, Lianbin Niu
Summary: In this study, the effect of TmPyPb thickness on the performance of OLEDs was investigated. It was found that increasing the thickness of TmPyPb promotes the triplet-charge annihilation process, resulting in a decrease in the maximum luminance of the devices. The concentration and lifetime of singlet polaron pairs and triplet excitons were found to be regulated by the bias voltage and temperature. Additionally, the MEL responses of the TmPyPb-ETL device showed a W-linear pattern attributed to the combined effect of hyperfine interaction and Zeeman splitting. These findings provide insights into the exciton recombination and annihilation processes in OLEDs.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Liang-Chun Lin, Tanner Smith, Qianxiang Ai, Brandon K. Rugg, Chad Risko, John E. Anthony, Niels H. Damrauer, Justin C. Johnson
Summary: In this study, a pyrene-bridged parallel tetracene dimer (TPT) with optimized interchromophore coupling strength was synthesized. The long-lived and strongly spin-polarized multiexciton quintet state, (TT)-T-5, was observed through transient absorption and electron paramagnetic resonance spectroscopy. The lifetime of (TT)-T-5 was estimated to be >35 μs, with a dephasing time (T-2) of 726 ns at 10 K for the corresponding qubit. The experimental results support recent theoretical models.
Article
Materials Science, Multidisciplinary
Jiayi Song, Yunxia Guan, Cheng Wang, Xi Bao, Wanjiao Li, Keao Peng, Shuang Xu, Lijia Chen, Lianbin Niu
Summary: In this study, the researchers investigated the properties of the thermally activated delayed fluorescence (TADF) material Px-CNP, focusing on its low singlet-triplet states energy gap and its ability to achieve reverse intersystem crossing (RISC) at room temperature with linear voltage dependence. Through the preparation of mCP:Px-CNP doped devices and measurement of the magneto-electroluminescence (MEL) effect, it was observed that the intensity of RISC showed a nonlinear dependence on voltage. By replacing the high-energy triplet material mCP with the low-energy triplet material Alq(3), the MEL curve changed to an intersystem crossing (ISC) line and exhibited a similar nonlinear voltage dependence. The study revealed the different energy transfer channels and energy loss in each device due to the different binding ability of Px-CNP triplet charge transfer (CT-C3) excitons by host materials with different triplet energy levels, resulting in distinct RISC and ISC patterns in the MEL. The voltage modulation of RISC and ISC in the devices was attributed to the concentration and lifetime changes of (CT)-C3 and T1 excitons through Dexter energy transfer (DET) and direct charge trapping (DCT) processes. These findings not only advance the understanding of RISC and ISC regulation in Px-CNP-based devices, but also provide insights for the efficient implementation of RISC process in TADF devices and the controllable application of (CT)-C3.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Xiantong Tang, Linyao Tu, Xi Zhao, Jing Chen, Yaru Ning, Fengjiao Wu, Zuhong Xiong
Summary: The aggregation behavior of rubrene molecules in rubrene-doped organic light-emitting diodes depends on the host material, either forming J-type or H-type aggregation. The H-type aggregation is attributed to the increased steric hindrance between rubrene molecules due to the unique molecular structures of the host materials. This H-type aggregation enhances the fluorescence of the devices and can be attributed to the intensified triplet-triplet annihilation process.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Samuel H. Amsterdam, Trevor LaMountain, Teodor K. Stanev, Vinod K. Sangwan, Rafael Lopez-Arteaga, Suyog Padgaonkar, Kenji Watanabe, Takashi Taniguchi, Emily A. Weiss, Tobin J. Marks, Mark C. Hersam, Nathaniel P. Stern
Summary: This study reports the morphology and temperature-dependent optical properties of pentacene films grown on hBN, showing differences in growth modality compared to SiO2 substrates, and demonstrates that using vdW materials provides a pathway for controlling optoelectronic functionality in molecular thin films.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Matthew W. Brett, Liselotte C. Nass, Calum K. Gordon, Lara D. Browne, Bridget L. Stocker, Michael B. Price, Mattie S. M. Timmer, Nathaniel J. L. K. Davis
Summary: Photon multiplication is a promising approach for surpassing the theoretical limit of single-junction photovoltaic cells. This study focuses on singlet fission-based photon multipliers using tetracene chromophores and lead sulfide quantum dots. By controlling the design and synthesis of novel tetracene chromophores and the shelling of the quantum dots, significant improvements in photoluminescence efficiencies have been achieved. However, the wavelength dependence of the improved photoluminescence efficiency cannot be solely attributed to singlet fission.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Biswajit Manna, Amitabha Nandi
Summary: Two types of nanosized-aggregates, ZnOEP NA and PtOEP NA, show distinct characteristics in the processes of fast triplet formation, excitonic decay, and diffusion. The triplet excitons exhibit slower diffusion rates, while the possible involvement of a singlet-triplet cooperative diffusion mechanism in ZnOEP NA results in a faster triplet diffusion compared to PtOEP NA.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Review
Polymer Science
Ting Wang, Bo-Yang Zhang, Hao-Li Zhang
Summary: Singlet fission, a process that enables overcoming the limits of photoenergy conversion, has been extensively studied in the past decade. This review discusses the recent developments, mechanisms, and applications of singlet fission materials in photovoltaics.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ashley M. Conley, Rachel A. Dziatko, Karl S. Westendorff, Anna Sviripa, Stephanie M. Guthrie, Zhuo Chen, Kevin H. Stone, Arthur E. Bragg, Christopher Paolucci, Joshua J. Choi, Gaurav Giri
Summary: Singlet fission, a sensitive process to the degree of electronic coupling within a molecular packing structure, can be affected by variations in molecular packing, ultimately influencing the harvesting of triplets for electricity in organic photovoltaic devices. In this study, six phase-pure molecular packing structures of TIPS-pentacene with varying optoelectronic properties are isolated using lead halide perovskites as crystalline surfaces for crystallization. The results show that perovskite-templating allows for closer packing of TIPS-pentacene molecules, which speeds up triplet-triplet separation and recombination, offsetting minor variations in molecular packing.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Biswajit Manna, Amitabha Nandi, Bal Govind Vats
Summary: Nanoaggregate formation of 1,6-Diphenyl-1,3,5-hexatriene (DPHT) leads to nearly isoergic singlet fission with prompt triplet pair production and subsequent generation of separated triplet excitons. The separated triplet exciton yield is high, but it also results in back transferred singlet excitons which can participate in singlet fission process again or decay through defect trapping. Defect trapping of photogenerated and re-generated singlet excitons plays a detrimental role in the overall triplet yield when compared to crystalline forms of the same molecule.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Anna K. Hailey, Szu-Ying Wang, Yuanzhen Chen, Marcia M. Payne, John E. Anthony, Vitaly Podzorov, Yueh-Lin Loo
ADVANCED FUNCTIONAL MATERIALS
(2015)
Article
Chemistry, Multidisciplinary
Hee Taek Yi, Zhihua Chen, Antonio Facchetti, Vitaly Podzorov
ADVANCED FUNCTIONAL MATERIALS
(2016)
Editorial Material
Chemistry, Physical
X. -Y. Zhu, V. Podzorov
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2015)
Article
Multidisciplinary Sciences
P. Irkhin, H. Najafov, V. Podzorov
SCIENTIFIC REPORTS
(2015)
Article
Materials Science, Multidisciplinary
Ming-Ling Yeh, Szu-Ying Wang, Josue F. Martinez Hardigree, Vitaly Podzorov, Howard E. Katz
JOURNAL OF MATERIALS CHEMISTRY C
(2015)
Editorial Material
Chemistry, Multidisciplinary
Beatrice Fraboni, Alessandro Fraleoni-Morgera, Yves Geerts, Alberto Morpurgo, Vitaly Podzorov
ADVANCED FUNCTIONAL MATERIALS
(2016)
Article
Chemistry, Multidisciplinary
Hee Taek Yi, Xiaoxi Wu, Xiaoyang Zhu, Vitaly Podzorov
ADVANCED MATERIALS
(2016)
Article
Multidisciplinary Sciences
Haoxing Zhang, Hailong Liu, Yali Chen, Xu Yang, Panfei Wang, Tongzheng Liu, Min Deng, Bo Qin, Cristina Correia, Seungbaek Lee, Jungjin Kim, Melanie Sparks, Asha A. Nair, Debra L. Evans, Krishna R. Kalari, Pumin Zhang, Liewei Wang, Zhongsheng You, Scott H. Kaufmann, Zhenkun Lou, Huadong Pei
NATURE COMMUNICATIONS
(2016)
Article
Physics, Applied
Y. Chen, H. T. Yi, V. Podzorov
PHYSICAL REVIEW APPLIED
(2016)
Article
Engineering, Electrical & Electronic
Leslie Carman, H. Paul Martinez, Lars Voss, Steven Hunter, Patrick Beck, Natalia Zaitseva, Stephen A. Payne, Pavel Irkhin, Hyun Ho Choi, Vitaly Podzorov
IEEE TRANSACTIONS ON NUCLEAR SCIENCE
(2017)
Article
Materials Science, Multidisciplinary
Ryo Fujimoto, Shun Watanabe, Yu Yamashita, Junto Tsurumi, Hiroyuki Matsui, Tomokatsu Kushida, Chikahiko Mitsui, Hee Taek Yi, Vitaly Podzorov, Jun Takeya
ORGANIC ELECTRONICS
(2017)
Article
Physics, Applied
B. Lee, Y. Chen, A. Cook, A. Zakhidov, V. Podzorov
JOURNAL OF APPLIED PHYSICS
(2014)
Article
Multidisciplinary Sciences
H. T. Yi, N. Gartstein, V. Podzorov
SCIENTIFIC REPORTS
(2016)
Article
Nanoscience & Nanotechnology
Hyun Ho Choi, Hikmet Najafov, Nikolai Kharlamov, Denis V. Kaznetsov, Sergei I. Didenko, Kilwon Cho, Alejandro L. Briseno, Vitaly Podzorov
ACS APPLIED MATERIALS & INTERFACES
(2017)
Article
Chemistry, Physical
Michael A. Fusella, Siyu Yang, Kevin Abbasi, Hyun Ho Cho, Zhuozhi Yao, Vitaly Podzorov, Amir Avishai, Barry P. Rand
CHEMISTRY OF MATERIALS
(2017)
