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Huang YJ, Chen HC, Lin HK, Wei KH. Doping ZnO Electron Transport Layers with MoS 2 Nanosheets Enhances the Efficiency of Polymer Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2018; 10:20196-20204. [PMID: 29783839 DOI: 10.1021/acsami.8b06413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this study, we incorporated molybdenum disulfide (MoS2) nanosheets into sol-gel processing of zinc oxide (ZnO) to form ZnO:MoS2 composites for use as electron transport layers (ETLs) in inverted polymer solar cells featuring a binary bulk heterojunction active layer. We could effectively tune the energy band of the ZnO:MoS2 composite film from 4.45 to 4.22 eV by varying the content of MoS2 up to 0.5 wt %, such that the composite was suitable for use in bulk heterojunction photovoltaic devices based on poly[bis(5-(2-ethylhexyl)thien-2-yl)benzodithiophene- alt-(4-(2-ethylhexyl)-3-fluorothienothiophene)-2-carboxylate-2,6-diyl] (PTB7-TH)/phenyl-C71-butryric acid methyl ester (PC71BM). In particular, the power conversion efficiency (PCE) of the PTB7-TH/PC71BM (1:1.5, w/w) device incorporating the ZnO:MoS2 (0.5 wt %) composite layer as the ETL was 10.1%, up from 8.8% for the corresponding device featuring ZnO alone as the ETL, a relative increase of 15%. Incorporating a small amount of MoS2 nanosheets into the ETL altered the morphology of the ETL and resulted in enhanced current densities, fill factors, and PCEs for the devices. We used ultraviolet photoelectron spectroscopy, synchrotron grazing incidence wide-/small-angle X-ray scattering, atomic force microscopy, and transmission electron microscopy to characterize the energy band structures, internal structures, surface roughness, and morphologies, respectively, of the ZnO:MoS2 composite films.
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Choi J, Jo JW, de Arquer FPG, Zhao YB, Sun B, Kim J, Choi MJ, Baek SW, Proppe AH, Seifitokaldani A, Nam DH, Li P, Ouellette O, Kim Y, Voznyy O, Hoogland S, Kelley SO, Lu ZH, Sargent EH. Activated Electron-Transport Layers for Infrared Quantum Dot Optoelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801720. [PMID: 29808501 DOI: 10.1002/adma.201801720] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/14/2018] [Indexed: 06/08/2023]
Abstract
Photovoltaic (PV) materials such as perovskites and silicon are generally unabsorptive at wavelengths longer than 1100 nm, leaving a significant portion of the IR solar spectrum unharvested. Small-bandgap colloidal quantum dots (CQDs) are a promising platform to offer tandem complementary IR PV solutions. Today, the best performing CQD PVs use zinc oxide (ZnO) as an electron-transport layer. However, these electrodes require ultraviolet (UV)-light activation to overcome the low carrier density of ZnO, precluding the realization of CQD tandem photovoltaics. Here, a new sol-gel UV-free electrode based on Al/Cl hybrid doping of ZnO (CAZO) is developed. Al heterovalent doping provides a strong n-type character while Cl surface passivation leads to a more favorable band alignment for electron extraction. CAZO CQD IR solar cell devices exhibit, at wavelengths beyond the Si bandgap, an external quantum efficiency of 73%, leading to an additional 0.92% IR power conversion efficiency without UV activation. Conventional ZnO devices, on the other hand, add fewer than 0.01 power points at these operating conditions.
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Affiliation(s)
- Jongmin Choi
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Jea Woong Jo
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - F Pelayo García de Arquer
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Yong-Biao Zhao
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
- Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario, M5S 3E4, Canada
| | - Bin Sun
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Junghwan Kim
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Min-Jae Choi
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Se-Woong Baek
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Andrew H Proppe
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3G4, Canada
| | - Ali Seifitokaldani
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Dae-Hyun Nam
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Peicheng Li
- Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario, M5S 3E4, Canada
| | - Olivier Ouellette
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Younghoon Kim
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Oleksandr Voznyy
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Sjoerd Hoogland
- Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario, M5S 3E4, Canada
| | - Shana O Kelley
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3G4, Canada
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada
| | - Zheng-Hong Lu
- Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario, M5S 3E4, Canada
| | - Edward H Sargent
- Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
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Wang R, Wu X, Xu K, Zhou W, Shang Y, Tang H, Chen H, Ning Z. Highly Efficient Inverted Structural Quantum Dot Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30. [PMID: 29315851 DOI: 10.1002/adma.201704882] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/08/2017] [Indexed: 05/04/2023]
Abstract
Highly efficient PbS colloidal quantum dot (QD) solar cells based on an inverted structure have been missing for a long time. The bottlenecks are the construction of an effective p-n heterojunction at the illumination side with smooth band alignment and the absence of serious interface carrier recombination. Here, solution-processed nickel oxide (NiO) as the p-type layer and lead sulfide (PbS) QDs with iodide ligand as the n-type layer are explored to build a p-n heterojunction at the illumination side. The large depletion region in the QD layer at the illumination side leads to high photocurrent. Interface carrier recombination at the interface is effectively prohibited by inserting a layer of slightly doped p-type QDs with 1,2-ethanedithiol as ligands, leading to improved voltage of the device. Based on this graded device structure design, the efficiency of inverted structural heterojunction PbS QD solar cells is improved to 9.7%, one time higher than the highest efficiency achieved before.
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Affiliation(s)
- Ruili Wang
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
- Shanghai Institute of Ceramic, Chinese Academy of Sciences, Shanghai, 200050, P. R. China
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xun Wu
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
| | - Kaimin Xu
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
| | - Wenjia Zhou
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
| | - Yuequn Shang
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
| | - Haoying Tang
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
| | - Hao Chen
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
| | - Zhijun Ning
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, 201210, P.R. China
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Bi Y, Pradhan S, Gupta S, Akgul MZ, Stavrinadis A, Konstantatos G. Infrared Solution-Processed Quantum Dot Solar Cells Reaching External Quantum Efficiency of 80% at 1.35 µm and J sc in Excess of 34 mA cm -2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:1704928. [PMID: 29315877 DOI: 10.1002/adma.201704928] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Developing low-cost photovoltaic absorbers that can harvest the short-wave infrared (SWIR) part of the solar spectrum, which remains unharnessed by current Si-based and perovskite photovoltaic technologies, is a prerequisite for making high-efficiency, low-cost tandem solar cells. Here, infrared PbS colloidal quantum dot (CQD) solar cells employing a hybrid inorganic-organic ligand exchange process that results in an external quantum efficiency of 80% at 1.35 µm are reported, leading to a short-circuit current density of 34 mA cm-2 and a power conversion efficiency (PCE) up to 7.9%, which is a current record for SWIR CQD solar cells. When this cell is placed at the back of an MAPbI3 perovskite film, it delivers an extra 3.3% PCE by harnessing light beyond 750 nm.
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Affiliation(s)
- Yu Bi
- ICFO (Institut de Ciencies Fotoniques), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels (Barcelona), Spain
| | - Santanu Pradhan
- ICFO (Institut de Ciencies Fotoniques), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels (Barcelona), Spain
| | - Shuchi Gupta
- ICFO (Institut de Ciencies Fotoniques), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels (Barcelona), Spain
| | - Mehmet Zafer Akgul
- ICFO (Institut de Ciencies Fotoniques), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels (Barcelona), Spain
| | - Alexandros Stavrinadis
- ICFO (Institut de Ciencies Fotoniques), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels (Barcelona), Spain
| | - Gerasimos Konstantatos
- ICFO (Institut de Ciencies Fotoniques), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels (Barcelona), Spain
- ICREA (Institució Catalana de Recerca i Estudis Avançats), Passeig Lluís Companys 23, 08010, Barcelona, Spain
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