scispace - formally typeset
Search or ask a question
Author

Chenxi Li

Bio: Chenxi Li is an academic researcher from Nankai University. The author has contributed to research in topics: Organic solar cell & Materials science. The author has an hindex of 38, co-authored 93 publications receiving 7223 citations.


Papers
More filters
Journal ArticleDOI
14 Sep 2018-Science
TL;DR: In this article, a semi-empirical model analysis and using the tandem cell strategy to overcome the low charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption was performed.
Abstract: Although organic photovoltaic (OPV) cells have many advantages, their performance still lags far behind that of other photovoltaic platforms. A fundamental reason for their low performance is the low charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption. In this work, guided by a semi-empirical model analysis and using the tandem cell strategy to overcome such issues, and taking advantage of the high diversity and easily tunable band structure of organic materials, a record and certified 17.29% power conversion efficiency for a two-terminal monolithic solution-processed tandem OPV is achieved.

2,165 citations

Journal ArticleDOI
TL;DR: The better PCEs were achieved by improving the short-circuit current density without sacrificing the high open-circuits voltage and fill factor through the strategy of incorporating the advantages of both conventional small molecules and polymers for OPVs.
Abstract: Three small molecules named DR3TBDTT, DR3TBDTT-HD, and DR3TBD2T with a benzo[1,2-b:4,5-b']dithiophene (BDT) unit as the central building block have been designed and synthesized for solution-processed bulk-heterojunction solar cells. Power conversion efficiencies (PCEs) of 8.12% (certified 7.61%) and 8.02% under AM 1.5G irradiation (100 mW cm(-2)) have been achieved for DR3TBDTT- and DR3TBDT2T-based organic photovoltaic devices (OPVs) with PC71BM as the acceptor, respectively. The better PCEs were achieved by improving the short-circuit current density without sacrificing the high open-circuit voltage and fill factor through the strategy of incorporating the advantages of both conventional small molecules and polymers for OPVs.

680 citations

Journal ArticleDOI
TL;DR: The results demonstrate that structure fine turning could cause significant performance difference and with that the performance of solution-processed small-molecule solar cells can indeed be comparable with or even surpass their polymer counterparts.
Abstract: Small molecules, namely, DCAO3TBDT and DR3TBDT, with 2-ethylhexoxy substituted BDT as the central building block and octyl cyanoacetate and 3-ethylrhodanine as different terminal units with the same linkage of dioctyltertthiophene, have been designed and synthesized. The photovoltaic properties of these two molecules as donors and fullerene derivatives as the acceptors in bulk heterojunction solar cells are studied. Among them, DR3TBDT shows excellent photovoltaic performance, and power conversion efficiency as high as 7.38% (certified 7.10%) under AM 1.5G irradiation (100 mW cm–2) has been achieved using the simple solution spin-coating fabrication process, which is the highest efficiency reported to date for any small-molecule-based solar cells. The results demonstrate that structure fine turning could cause significant performance difference and with that the performance of solution-processed small-molecule solar cells can indeed be comparable with or even surpass their polymer counterparts.

559 citations

Journal ArticleDOI
TL;DR: The results demonstrate that the BDT unit could also be applied for designing NF-acceptors, and the fused-ring benzodi(cyclopentadithiophene) unit is a prospective block for designing new NF- acceptors with excellent performance.
Abstract: A new nonfullerene small molecule with acceptor–donor–acceptor (A–D–A) structure, namely, NFBDT, based on a heptacyclic benzodi(cyclopentadithiophene) (FBDT) unit using benzo[1,2-b:4,5-b′]dithiophene as the core unit, was designed and synthesized. Its absorption ability, energy levels, thermal stability, as well as photovoltaic performances were fully investigated. NFBDT exhibits a low optical bandgap of 1.56 eV resulting in wide and efficient absorption that covered the range from 600 to 800 nm, and suitable energy levels as an electron acceptor. With the widely used and successful wide bandgap polymer PBDB-T selected as the electron donor material, an optimized PCE of 10.42% was obtained for the PBDB-T:NFBDT-based device with an outstanding short-circuit current density of 17.85 mA cm–2 under AM 1.5G irradiation (100 mW cm–2), which is so far among the highest performance of NF-OSC devices. These results demonstrate that the BDT unit could also be applied for designing NF-acceptors, and the fused-ring b...

434 citations

Journal ArticleDOI
TL;DR: The FDICTF modified by fusing the fluorene core in a precursor, yields 10.06% high power conversion efficiency, and demonstrates that the ladder and fused core backbone in A-D-A structure molecules is an effective design strategy for high-performance nonfullerene acceptors.
Abstract: Nonfullerene acceptor FDICTF (2,9-bis(2methylene-(3-(1,1-dicyanomethylene)indanone))-7,​12-​dihydro-​4,​4,​7,​7,​12,​12-​hexaoctyl-​4H-​cyclopenta[2″,​1″:5,​6;3″,​4″:5',​6']​diindeno[1,​2-​b:1',​2'-​b']dithiophene) modified by fusing the fluorene core in a precursor, yields 10.06% high power conversion efficiency, and demonstrates that the ladder and fused core backbone in A-D-A structure molecules is an effective design strategy for high-performance nonfullerene acceptors.

271 citations


Cited by
More filters
Journal ArticleDOI
17 Apr 2019-Joule
TL;DR: In this paper, a ladder-type electron-deficient core-based central fused ring (Dithienothiophen[3.2-b]- pyrrolobenzothiadiazole) with a benzothiadiadiazoles (BT) core was proposed to fine-tune its absorption and electron affinity.

3,513 citations

Journal ArticleDOI
14 Sep 2018-Science
TL;DR: In this article, a semi-empirical model analysis and using the tandem cell strategy to overcome the low charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption was performed.
Abstract: Although organic photovoltaic (OPV) cells have many advantages, their performance still lags far behind that of other photovoltaic platforms. A fundamental reason for their low performance is the low charge mobility of organic materials, leading to a limit on the active-layer thickness and efficient light absorption. In this work, guided by a semi-empirical model analysis and using the tandem cell strategy to overcome such issues, and taking advantage of the high diversity and easily tunable band structure of organic materials, a record and certified 17.29% power conversion efficiency for a two-terminal monolithic solution-processed tandem OPV is achieved.

2,165 citations