Browsing by Author "Hong, Ling"

Now showing 1 - 4 of 4

A chlorinated nonacyclic carbazole-based acceptor affords over 15% efficiency in organic solar cells
(2020-01-21)
Chen, Tsung-Wei
;
Peng, Kuan-Lin
;
Lin, You-Wei
;
Su, Yi-Jia
;
Ma, Ko-Jui
In this contribution, a dithienocyclopentacarbazole (DTC)-based and two dithieno[3,2-b]thiophenecyclopentacarbazole (DTTC)-based non-fullerene acceptors (NFAs) named DTC-4F, DTTC-4F and DTTC-4Cl were exploited to elucidate the effects of conjugation extension and end group chlorination. DTTC-4F was designed through conjugation extension on the basis of DTC-4F by fusing one additional thiophene on both flanks of the heptacyclic DTC core, generating the nonacyclic DTTC core. Compared with DTC-4F, DTTC-4F features up-shifted energy levels, red-shifted absorption and enhanced pi-pi interaction. PM6:DTTC-4F exhibits a decent PCE of 13.89% with a V-OC of 0.95 V, a J(SC) of 21.66 mA cm(-2) and a FF of 67.60%. Although DTTC-4F affords a reduced FF compared to DTC-4F, a DTTC-4F-based device delivers a higher PCE than DTC-4F-based devices due to the extended absorption range of DTCC-4F in comparison with DTC-4F. Since chlorinated NFAs are known to possess stronger pi-pi interaction than fluorinated NFAs, DTTC-4Cl was therefore synthesized by end-capping DTTC core with 2Cl-IC groups instead of 2F-IC groups. Moreover, DTTC-4Cl demonstrates a red-shifted absorption in comparison with DTTC-4F, which is beneficial for light-harvesting. Overall, PM6:DTTC-4Cl affords an outstanding PCE of 15.42% with a V-OC of 0.92 V, a J(SC) of 22.64 mA cm(-2) and a FF of 74.04%, which is the record PCE observed in carbazole-based NFAs.
Chlorinated Carbon-Bridged and Silicon-Bridged Carbazole-Based Nonfullerene Acceptors Manifest Synergistic Enhancement in Ternary Organic Solar Cell with Efficiency over 15%
(1970-01-01)
Chen, Tsung-Wei
;
Yu, Jun-Yan
;
Lin, You-Wei
;
Peng, Shih-Hao
;
Wu, Shang-Hsuan
Herein, two novel nonfullerene acceptors (NFAs), DTCC-4Cl and DTSiC-4Cl, are synthesized by end-capping dithienocyclopentacarbazole (DTCC) and dithieno-silolocarbazole (DTSiC) cores with chlorinated IC (2Cl-IC) units, respectively. With the better-known advantage of having the extraordinary sigma*-pi* conjugation of silole unit embedded in the DTSiC core, DTSiC-4Cl manifests upshifted lowest unoccupied molecular orbital (LUMO), blue-shifted absorption, and increased pi-pi interaction in comparison with DTCC-4Cl. Furthermore, to elucidate the effect of bridging atoms on the photovoltaic performance, T1 is selected as the polymer donor to be blended with DTCC-4Cl and DTSiC-4Cl. T1:DTCC-4Cl-based devices exhibit a fine power conversion efficiency (PCE) of 14.43% and T1:DTSiC-4Cl-based devices exhibit a comparable PCE of 14.46%. Interestingly, the T1:DTSiC-4Cl-based devices demonstrate an additive-free feature, which is worthy of further applications. From the perspective of constructing high-performance ternary devices, DTCC-4Cl is expected to possess excellent compatibility with DTSiC-4Cl owing to its structural similarity. As anticipated, the ternary T1:DTSiC-4Cl:DTCC-4Cl-based device outperforms the binary T1:DTCC-4Cl and T1:DTSiC-4Cl-based devices, affording a decent PCE of 15.04% with aV(OC)of 0.97 V, aJ(SC) of 20.80 mA cm(-2), and an FF of 74.55% without any additive.
Highly efficient and stable organic solar cell modules processed by blade coating with 5.6% module efficiency and active area of 216 cm(2)
(2019-03-01)
Huang, Kuan-Min
;
Wong, Ying Qian
;
Lin, Man-Chun
;
Chen, Chao-Hsuan
;
Liao, Chung-Hung
In this study, an efficient and stable large-area blade-coated organic solar cell (OSC) module with an active area of 216 cm(2) (16 elementary cells connected in series) is demonstrated by combining appropriate thermal annealing treatment with the use of 4,4 '-(((methyl(4-sulphonatobutyl)ammonio)bis(propane-3,1-diyl))bis(dimethyl-ammoniumdiyl))bis-(butane-1-sulfonate) (MSAPBS) as the cathode interfacial layer. For the opaque device using poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b ']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PBDTTT-EFT (PTB7-Th)):[6,6]-phenyl C-71-butyric acid methyl ester (PC71BM) blend film as the active layer, the power conversion efficiency (PCE) of 5.6% is achieved under AM 1.5G solar light illumination. Very encouragingly, our strategy can be applicable for semitransparent OSCs, and a remarkable PCE up to 4.5% is observed. To the best of our knowledge, the PCE of 5.6% for opaque device and 4.5% for semitransparent device represent the highest PCE ever reported for OSCs with the active area exceeding 100 cm(2). The devices also show an impressive stability under outdoor environment, where the efficiency decay is less than 30% for 60 days. Our findings can pave the way toward the development of organic solar cell modules with high performance and long-term stability.
Single-Junction Organic Solar Cell Containing a Fluorinated Heptacyclic Carbazole-Based Ladder-Type Acceptor Affords over 13% Efficiency with Solution-Processed Cross-Linkable Fullerene as an Interfacial Layer
(2019-08-28)
Chen, Tsung-Wei
;
Chang, Chia-Chih
;
Hsiao, Yu-Tang
;
Chan, ChoonKee
;
Hong, Ling
In this article, a fluorinated heptacyclic dithienocyclopentacarbazole (DTC)-based non-fullerene acceptor (NFA), DTC(4Ph)-4FIC, is synthesized and blended with J71, PBDB-T, and PBDB-TF, featuring complementary absorption and well-matched energy levels. The DTC(4Ph)-4FIC neat film exhibits face-on preference, whereas the nonfluorinated counterpart, DTC(4Ph)-IC, exhibits edge-on preference; this unique feature owing to fluorination in DTC-based NFAs is observed for the first time. More importantly, DTC(4Ph)-4FIC exhibits improved power conversion efficiencies (PCEs) of 10.92 and 10.41% in J71- and PBDB-T-containing devices, while the devices that employed DTC(4Ph)-IC afford PCEs of 7.76 and 9.48%, respectively. Because PBDB-TF is known to exhibit lower energy levels than J71 and PBDB-T, the corresponding device affords a V-OC of 0.95 V, a J(SC) of 18.29 mA cm(-2), a FF of 75.70%, and a PCE of 13.15%, which is 20 and 26% higher than J71- and PBDB-T-containing devices. Furthermore, the inverted device containing the PBDB-TF:DTC(4Ph)-4FIC blend is fabricated using cross-linkable fullerene (C-PCBSD) as the cathode interlayer, affording a decent PCE of 13.36%, with a V-OC of 0.94 V, a J(SC) of 20.20 mA cm(-2), and a FF of 70.42%.