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Eisner F, Foot G, Yan J, Azzouzi M, Georgiadou DG, Sit WY, Firdaus Y, Zhang G, Lin YH, Yip HL, Anthopoulos TD, Nelson J. Emissive Charge-Transfer States at Hybrid Inorganic/Organic Heterojunctions Enable Low Non-Radiative Recombination and High-Performance Photodetectors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2104654. [PMID: 34611947 DOI: 10.1002/adma.202104654] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Hybrid devices based on a heterojunction between inorganic and organic semiconductors have offered a means to combine the advantages of both classes of materials in optoelectronic devices, but, in practice, the performance of such devices has often been disappointing. Here, it is demonstrated that charge generation in hybrid inorganic-organic heterojunctions consisting of copper thiocyanate (CuSCN) and a variety of molecular acceptors (ITIC, IT-4F, Y6, PC70 BM, C70 , C60 ) proceeds via emissive charge-transfer (CT) states analogous to those found at all-organic heterojunctions. Importantly, contrary to what has been observed at previous organic-inorganic heterojunctions, the dissociation of the CT-exciton and subsequent charge separation is efficient, allowing the fabrication of planar photovoltaic devices with very low non-radiative voltage losses (0.21 ± 0.02 V). It is shown that such low non-radiative recombination enables the fabrication of simple and cost-effective near-IR (NIR) detectors with extremely low dark current (4 pA cm-2 ) and noise spectral density (3 fA Hz-1/2 ) at no external bias, leading to specific detectivities at NIR wavelengths of just under 1013 Jones, close to the performance of commercial silicon photodetectors. It is believed that this work demonstrates the possibility for hybrid heterojunctions to exploit the unique properties of both inorganic and organic semiconductors for high-performance opto-electronic devices.
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Affiliation(s)
- Flurin Eisner
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Georgie Foot
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Jun Yan
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Mohammed Azzouzi
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Dimitra G Georgiadou
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
- Centre for Electronics Frontiers, Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ, UK
| | - Wai Yu Sit
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Yuliar Firdaus
- Division of Physical Sciences and Engineering and KAUST Solar Centre, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
- Research Center for Electronics and Telecommunication, Indonesian Institute of Science, Jalan Sangkuriang Komplek LIPI Building 20 level 4, Bandung, 40135, Indonesia
| | - Guichuan Zhang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yen-Hung Lin
- Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Hin-Lap Yip
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Thomas D Anthopoulos
- Division of Physical Sciences and Engineering and KAUST Solar Centre, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Jenny Nelson
- Department of Physics, Imperial College London, South Kensington, London, SW7 2AZ, UK
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Prashanthan K, Naydenov B, Lips K, Unger E, MacQueen RW. Interdependence of photon upconversion performance and antisolvent processing in thin-film halide perovskite-sensitized triplet-triplet annihilators. J Chem Phys 2020; 153:164711. [PMID: 33138395 DOI: 10.1063/5.0026564] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We prepared triplet-triplet annihilation photon upconverters combining thin-film methylammonium lead iodide (MAPI) perovskite with a rubrene annihilator in a bilayer structure. Excitation of the perovskite film leads to delayed, upconverted photoluminescence emitted from the annihilator layer, with triplet excitation of the rubrene being driven by carriers excited in the perovskite layer. To better understand the connections between the semiconductor properties of the perovskite film and the upconversion efficiency, we deliberately varied the perovskite film properties by modifying two spin-coating conditions, namely, the choice of antisolvent and the antisolvent dripping time, and then studied the resulting photon upconversion performance with a standard annihilator layer. A stronger upconversion effect was exhibited when the perovskite films displayed brighter and more uniform photoluminescence. Both properties were sensitive to the antisolvent dripping time and were maximized for a dripping time of 20 s (measured relative to the end of the spin-coating program). Surprisingly, the choice of antisolvent had a significant effect on the upconversion performance, with anisole-treated films yielding on average a tenfold increase in upconversion intensity compared to the chlorobenzene-treated equivalent. This performance difference was correlated with the carrier lifetime in the perovskite film, which was 52 ns and 306 ns in the brightest chlorobenzene and anisole-treated films, respectively. Since the bulk properties of the anisole- and chlorobenzene-treated films were virtually identical, we concluded that differences in the defect density at the MAPI/rubrene interface, linked to the choice of antisolvent, must be responsible for the differing upconversion performance.
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Affiliation(s)
- Karunanantharajah Prashanthan
- Department Spins in Energy Conversion and Quantum Information Science (EE-ASPIN), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany
| | - Boris Naydenov
- Department Spins in Energy Conversion and Quantum Information Science (EE-ASPIN), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany
| | - Klaus Lips
- Department Spins in Energy Conversion and Quantum Information Science (EE-ASPIN), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany
| | - Eva Unger
- Young Investigator Group Hybrid Materials Formation and Scaling, Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH, Berlin, Germany
| | - Rowan W MacQueen
- Department Spins in Energy Conversion and Quantum Information Science (EE-ASPIN), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany
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Kafle TR, Kattel B, Yao P, Zereshki P, Zhao H, Chan WL. Effect of the Interfacial Energy Landscape on Photoinduced Charge Generation at the ZnPc/MoS 2 Interface. J Am Chem Soc 2019; 141:11328-11336. [PMID: 31259543 DOI: 10.1021/jacs.9b05893] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Monolayer transition-metal dichalcogenide crystals (TMDC) can be combined with other functional materials, such as organic molecules, to form a wide range of heterostructures with tailorable properties. Although a number of works have shown that ultrafast charge transfer (CT) can occur at organic/TMDC interfaces, conditions that would facilitate the separation of interfacial CT excitons into free carriers remain unclear. Here, time-resolved and steady-state photoemission spectroscopy are used to study the potential energy landscape, charge transfer, and exciton dynamics at the zinc phthalocyanine (ZnPc)/monolayer (ML) MoS2 and ZnPc/bulk MoS2 interfaces. Surprisingly, although both interfaces have a type-II band alignment and exhibit sub-100 fs CT, the CT excitons formed at the two interfaces show drastically different evolution dynamics. The ZnPc/ML-MoS2 behaves like typical donor-acceptor interfaces in which CT excitons dissociate into electron-hole pairs. On the contrary, back electron transfer occur at ZnPc/bulk-MoS2, which results in the formation of triplet excitons in ZnPc. The difference can be explained by the different amount of band bending found in the ZnPc film deposited on ML-MoS2 and bulk-MoS2. Our work illustrates that the potential energy landscape near the interface plays an important role in the charge separation behavior. Therefore, considering the energy level alignment at the interface alone is not enough for predicting whether free charges can be generated effectively from an interface.
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Affiliation(s)
- Tika R Kafle
- Department of Physics and Astronomy , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Bhupal Kattel
- Department of Physics and Astronomy , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Peng Yao
- Department of Physics and Astronomy , University of Kansas , Lawrence , Kansas 66045 , United States.,Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology , Beijing Jiaotong University , Beijing 100044 , China
| | - Peymon Zereshki
- Department of Physics and Astronomy , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Hui Zhao
- Department of Physics and Astronomy , University of Kansas , Lawrence , Kansas 66045 , United States
| | - Wai-Lun Chan
- Department of Physics and Astronomy , University of Kansas , Lawrence , Kansas 66045 , United States
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