- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Enhanced Photovoltaic Performance by Synergistic Effect of Chlorination and Selenophene ??-Bridge
摘要： In the rapid innovation of organic solar cells, polymer donor plays a significant role in achieving high power conversion efficiencies (PCEs). The strong intermolecular interactions and deep highest occupied molecular orbitals (HOMOs) of donor polymers will facilitate the favorable phase separation and high open-circuit voltage (Voc), resulting in the dramatic improvement of device performance. Herein, combined chlorination of 4,8-bis(thiophene-2-yl)-benzo[1,2-b:4,5-b′]-dithiophene (T-BDT) and selenophene π-bridges, a new polymer donor, named PBBSe-Cl, is designed and synthesized. Compared to its parent polymer without chlorine substitution and π-bridge (named PBB), PBBSe-Cl exhibits much stronger absorption, better molecular planarity, and improved molecular aggregations. Moreover, PBBSe-Cl shows favorable phase separation and bicontinuous interpenetrating network when blending with acceptor Y6. As a result, the inverted device based on PBBSe-Cl achieves a decent PCE of 14.44%, with synchronously improved short-circuit current density (Jsc) of 24.07 mA cm?2 and fill factor (FF) of 73.16%. However, its parent polymers PBB and PBBSe-H only present a relatively low device performance. In addition, a very low energy loss (Eloss) of 0.51 eV is realized for PBBSe-Cl-based devices. This investigation proves that introducing chlorine atoms on the conjugated side chains and selenophene π-bridges will stepwise increase the polymer solar cell efficiency due to the simultaneous enhancement of device current density and fill factor. The proper usage of chlorination and selenophene π-bridge is a facile and efficient strategy for high-performance solar conversion materials.
关键词： selenophene π-bridges,organic solar cells,power conversion efficiencies,chlorination,polymer donor
更新于2025-09-23 15:19:57
-
Chlorination <i>vs.</i> fluorination: a study of halogenated benzo[ <i>c</i> ][1,2,5]thiadiazole-based organic semiconducting dots for near-infrared cellular imaging
摘要： Red/near-infrared organic dyes are becoming increasingly widespread in biological applications. However, designing these dyes with long-wavelength emission, large Stokes shifts, and high fluorescence quantum efficiency is still a very challenging task. In this work, five donor-acceptor (D-A) red/near-infrared fluorophores based on different chlorinated/fluorinated benzo[c][1,2,5]thiadiazole units are designed and synthesized. The photophysical, theoretical calculations, and electrochemical properties explored in this study have proved that the introducing of chlorine atoms will lead to a lower HOMO level, stronger steric hindrance, and a relative lower quantum yield in solutions. When the organic dots are fabricated, the chlorinated dots demonstrate much higher fluorescence quantum yield, larger Stokes shift, and better photostability than that of the fluorinated dots. After labeling A549 cells, all the chlorinated/fluorinated dots exhibit high red emission intensities. All these results indicated that the subtle change in the halogen atom of the benzo[c][1,2,5]thiadiazole unit is a unique method to tune the photophysical properties of those materials, which also provides good guidelines to design highly efficient red/near-infrared molecules for cellular imaging applications.
关键词： 5]thiadiazole,organic semiconducting dots,chlorination,benzo[c][1,fluorination,near-infrared cellular imaging,2
更新于2025-09-23 15:19:57
-
Rational Design of Low Bandgap Polymers for Efficient Solar Cells with High Open-Circuit Voltage: The Profound Effect of Me and Cl Substituent with Similar Van Der Waals Radius
摘要： Generally, low bandgap materials-based photovoltaic devices have reduced open circuit voltage (VOC), and how to realize the trade-off between the low bandgap (Eg<1.6 eV) and high VOC (>0.9 V) could be critical to give efficient polymer solar cells, especially for high-performance semitransparent PSCs and tandem solar cells. Although lots of efforts have been made to address the issue, most results may be not gratifying. In this work, the polymer PTBTz-Cl based on the chlorination method and efficient thiazole-induced strategy was designed and synthesized, aiming at the deep HOMO energy level, and the enhanced backbone planarity caused by the weak noncovalent Cl···S interaction. In addition, the methyl-substituted polymer PTBTz-Me was constructed as the reference due to the similar van der Waals radius of side chain (CH3: 0.20 nm vs Cl: 0.18 nm). Encouragingly, in comparison with that of PTBTz-2, the newly synthesized polymers exhibit the red-shifted absorption spectra ranging from 300 to 770 nm, with obviously reduced Eg of ～1.6 eV. However, the function of Cl and Me substituent is different. Compared to the polymer PTBTz-Me, PTBTz-Cl exhibits a lower HOMO value, stronger crystallinity, and more compact intramolecular interactions. Consequently, the polymer PTBTz-Cl exhibits excellent photovoltaic performance with a notable VOC of 0.94 V and a PCE of 10.35%, which is ～11% higher than the 9.12% efficiency based on PTBTz-Me, and is also one of the highest values among polymer/fullerene solar cells. Moreover, a smaller photo energy loss (Eloss) of 0.64 eV is achieved, which is rare among the current high-performance polymer systems.
关键词： High open-circuit voltage,Low energy loss,Photovoltaic performance,Chlorination method,Polymer solar cell
更新于2025-09-11 14:15:04
-
Effects of chlorination on the fluorescence of seawater: Pronounced changes of emission intensity and their relationships with the formation of disinfection byproducts
摘要： Chlorination of coastal (CS) and deep ocean (DO) seawater was accompanied by a prominent decrease (of up to 70%) of the intensity of its emission which was measured using a 315 nm excitation wavelength. Deconvolution of the emission spectra of CS and DO seawater showed that these spectra comprised three Gauss-shaped bands. The intensities of two of these bands decreased rapidly as the halogenation proceeded. For both DO and CS seawater, two stages of changes of their fluorescence were observed. The first stage in which the relative changes of the fluorescence intensity (DF/F) were between zero to 0.30 and 0.40 was not accompanied by the release of individual disinfection byproduct (DBP) species. For DF/F values above the corresponding thresholds, the relative changes of fluorescence intensity were well correlated with the concentrations of individual DBP species such as trihalomethanes and haloacetonitriles. R2 values for CHBr3, CHBr2Cl and CHBrCl2 formed in DO seawater were 0.83, 0.80 and 0.68, respectively while for CS seawater, the corresponding R2 values were 0.91, 0.93 and 0.92. The presented data demonstrate that the intrinsic chemistry of DBP formation and dissolved organic matter (DOM) halogenation in seawater can be well quantified based on the examination of changes of its fluorescence. This approach can also be employed for practical monitoring of changes of properties of marine DOM and generation of DBPs in desalination, marine aquaculture and other processes.
关键词： Chlorination,Disinfection byproducts,Fluorescence,Seawater,Coastal,Correlation
更新于2025-09-04 15:30:14