Hai-Lang Jia
Nanjing University
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Featured researches published by Hai-Lang Jia.
Inorganic Chemistry | 2016
Wei Yan; Li-Juan Han; Hai-Lang Jia; Kang Shen; Ting Wang; He-Gen Zheng
Three Co(II) metal-organic frameworks (MOFs) were synthesized employing a rational design approach. On the basis of the different structures of three complexes, we tested their absorption properties toward two anionic dyes. The absorption results indicate that not only uncoordinated functional groups in the structure play an important role in adsorbing capacity but also physical forces can affect absorbing ability. Water stability testing shows that three crystals display high stability in aqueous solutions with different pH values. To our delight, the framework integrity of three complexes can be well-retained even after absorbing dyes.
Journal of Materials Chemistry | 2016
Hai-Lang Jia; Ming-Dao Zhang; Wei Yan; Xuehai Ju; He-Gen Zheng
We prepared three new push–pull dyes JA3, JA4 and JA0 through structure optimization, and applied them in DSSCs. Judicious molecular structure optimization of dyes can significantly improve the performance of DSSCs. Spirobifluorene as a building block was introduced onto the phenothiazine donor groups. Compared to JA1, the steric effect of the spirobifluorene building block can effectively reduce charge recombination by preventing the I3− of the electrolyte penetrating into the TiO2 surface, thus the Voc of JA3 increased from 701 mV to 800 mV. In order to further improve the light-harvesting ability of the DSSC, we introduced a benzothiadiazole unit (BTD) and prepared D–A–π–A dye JA4. As expected, the Jsc of JA4 increased from 12.32 to 14.43 mA cm−2 compared to that of JA3, and the device reached the highest PCE of 7.0%. Moreover, since extending the π-conjugated system is known to decrease the Voc of DSSC, the porphyrin unit was removed and dye JA0 was synthesized. Notably, the DSSC based on JA0 reached a very high Voc of 840 mV and a high PCE of 6.69%: to our knowledge, this is the highest Voc for DSSCs based on phenothiazine dyes with I−/I3− electrolyte.
New Journal of Chemistry | 2016
Hai-Lang Jia; Kang Shen; Xuehai Ju; Ming-Dao Zhang; He-Gen Zheng
Two new Y-shaped D–π–(A)2 type phenothiazine-based dyes (ZJA2 and ZJA3) were designed and synthesized for dye-sensitized solar cells (DSSCs). Compared to the single D–π–A analogue dye ZJA1, the Y-shaped dye with two carboxylic acid anchors was in favour of enhancing the performance of DSSCs. The FTIR spectra revealed that the dye ZJA2 molecules were anchored onto the TiO2 surface by two carboxylic acid anchors, which effectively increased the electron extraction channels. The steady-state emission spectra and time-resolved fluorescence experiments all indicated that the electron injection efficiency of dye ZJA2 was improved by the increased electron extraction channels, thus the Jsc of ZJA2 was greatly improved compared to dye ZJA1. In addition, benzene was used as the π-bridge for linking di-anchoring groups, combined with CDCA, thereby reducing the charge recombination. As a result, the PCE of the DSSC based on ZJA2 (4.55%) was 67% higher than the DSSC based on ZJA1 (2.72%). The Y-shaped D–π–(A)2 type phenothiazine-based dye ZJA3 containing two pyridine anchors was also investigated, and the DSSC based on ZJA3 showed a poor PCE (0.45%) due to the low dye loading.
Journal of Materials Chemistry | 2015
Hai-Lang Jia; Ming-Dao Zhang; Ze-Min Ju; He-Gen Zheng
We developed a novel efficient tridentate anchoring group which can anchor dyes onto the TiO2 surface via synchronously choosing Lewis acid sites and Bronsted acid sites of TiO2. For the purpose of comparing the traditional carboxylate anchoring group to picolinic acid, two new D–π–A porphyrin dyes (JA1 and JA2) differing only in anchoring groups have been synthesized and applied in dye-sensitized solar cells. Picolinic acid as an anchoring group in the dye JA2 not only extended the scope of the spectral response, but also improved the charge transport properties and enhanced the electron injection efficiency. The PCE of the JA1 based-device (carboxylate as the anchoring group) was 5.76%. The PCE of the JA2 based-device was 7.20%, which increased by 25% compared with JA1. The dye TTR2 was used as a cosensitizer; it would not just make up for the poor absorption of porphyrin dyes in the 470–550 nm range, but also would suppress the main dye aggregation and reduce the charge recombination rate. We found that the picolinic acid anchor was more suitable for the cosensitization system than the carboxylate anchor, for there was almost no competitive adsorption between JA2 and TTR2. The JA2 + TTR2 based-device showed the highest PCE of 8.98% under AM 1.5 G irradiation.
Journal of Materials Chemistry | 2014
Hai-Lang Jia; Ze-Min Ju; Hong-Xia Sun; Xuehai Ju; Ming-Dao Zhang; Xingfu Zhou; He-Gen Zheng
A series of novel panchromatic D–D–π–A porphyrin dyes have been synthesized and applied to dye-sensitized solar cells. Three porphyrin dyes named JP1, JP2 and JP3, and their photophysical and electrochemical properties and photovoltaic performance were investigated and compared with reference dye YD2-O-C8. 2-Hexylthiophene chromophores were introduced to the donor groups, which extended the π-conjugation system effectively, then broadened the range of spectral response and improved the charge separation between the donor and acceptor moieties in the excited state. Moreover, this paper used thiophene-2-carboxylic acid instead of the traditional benzoic acid as an anchor group, which can make the molecules arrange to tilted orientation when adsorbed on the TiO2 surface, and this may effectively suppress the dye aggregation and prevent charge recombination. These dyes were clearly red-shifted when compared with dye YD2-O-C8. Especially for dye JP3, its maximum absorption peak was red shifted 20 nm with respect to dye YD2-O-C8 from 645 to 665 nm, and the molar extinction coefficient (6.2 × 104 M−1 cm−1) of JP3 is double that of YD2-O-C8 (3.1 × 104 M−1 cm−1) at the Q band. Dye JP3 extended the spectral response to 750 nm. The density functional theory (DFT) calculations indicated that the electronic density of the HOMO was increased by the additional thiophene units in these dyes when compared with YD2-O-C8, and this will improve the conjugation and electron donating ability. The power conversion efficiencies of JP1, JP2 and JP3 are 5.09%, 5.62% and 6.40% respectively under AM 1.5G irradiation, which are 74.5%, 82.3% and 93.7% of the YD2-O-C8 based-device (6.83%) under the same conditions.
RSC Advances | 2015
Ze-Min Ju; Hai-Lang Jia; Xuehai Ju; Xingfu Zhou; Zhi-Qiang Shi; He-Gen Zheng; Ming-Dao Zhang
This paper focuses on the structure modification of triphenylamine dyes for efficient dye-sensitized solar cells (DSSCs). Three D–D–π–A dyes (TTR1–3), with triphenylamine moiety and its derivatives as the electron donor, thiophene ring as the π-bridge, and 2-(1,1-dicyanomethylene)rhodanine (DCRD) as the electron acceptor, were synthesized and fully characterized. Nanocrystalline TiO2-based DSSCs were fabricated using these dyes to investigate the effect of different donor groups introduced into triphenylamine on their photovoltaic performances. The overall power conversion efficiency (PCE) of DSSCs based on TTR1–3 with chenodeoxycholic acid (CDCA) coadsorbant are 5.20%, 5.71% and 6.30%, respectively, compared to 6.62% achieved with N719. Introduced heterocyclic group with alkyl lain into triphenylamine decreased dye absorbed amount but significantly improved the value of the open circuit voltage (Voc) and the short-circuit photocurrent (Jsc), which result from the fact that they can effectively suppress the charge recombination and prevent aggregation between adjacent molecules on TiO2. We also researched the effect of sensitization for single dyes on their photovoltaic performances. The PCEs of DSSCs soaked for 32 h increase slightly compared to those of DSSCs soaked for 16 h, which result from the adsorption quantity on the TiO2 surface. We found that, with soaking twice in 32 h, the Jsc and Voc were both obviously improved compared with soaking once in 32 h. These results provide a new approach for enhancing the photovoltaic performances of DSSCs based on single dye.
New Journal of Chemistry | 2018
Hai-Lang Jia; Zhi-Jie Peng; Yu-Chao Chen; Cheng-Yan Huang; Mingyun Guan
In this work, three D–A–π–A stereoscopic phenothiazine dyes JA0, JA6 and JA7 were prepared and applied in dye-sensitized solar cells. Spirobifluorene and long carbon chain units were introduced onto the donors of phenothiazine dyes to construct stereoscopic structures, this strategy can effectively suppress dye charge recombination by decreasing back reaction of the injected electrons with triiodide species in the electrolyte, the results show that the Voc values of the DSSCs based on JA0 and JA6 were both over 800 mV. To improve the spectral responsiveness of these dyes, the strongly electron-withdrawing benzothiadiazole unit (BTD) was introduced, and the spectral response of JA6 reached about 770 nm. In addition, it is very important for sensitizers to have suitable anchors, this determines the efficiency of charge injection and the degree of bonding between the sensitizer and semiconductor surface. In order to further improve the performance of DSSCs, carboxylic acid, cyanoacrylic acid and pyridine are all used as anchors in this work, and we investigated the optical properties, electrochemical properties, and photovoltaic performance of these dyes to analyze the influence of different anchors on dyes. The results show that cyanoacrylic acid is the best anchor for this series of dyes, which is very helpful to improve the light-harvesting ability of dyes; the DSSC based on JA6 with a cyanoacrylic acid anchor exhibited the highest PCE of 7.34%. In contrast, the PCE of the DSSC based on JA7 with a pyridine anchor was only 3.05%, this should be mainly due to its poor dye adsorption properties.
New Journal of Chemistry | 2018
Hai-Lang Jia; Zhi-Jie Peng; Mingyun Guan
Herein, we prepared two new zinc porphyrin dyes (JA4 and JA5) containing different anchoring groups and applied them in dye-sensitized solar cells. The hydrazide unit was used as an anchoring group for a DSSC, and the device based on the JA5 containing hydrazide anchor also shows a high PCE of 5.49% with a Jsc of 11.57 mA cm−2 and a Voc of 737 mV. COOH is the most common anchor, but it is prone to dissociate from the TiO2 surface, especially under alkaline conditions. Interestingly, the hydrazide anchor shows better water-stability under various aqueous conditions compared with the COOH anchor, including acidic, neutral and alkaline conditions. In addition, a hydrazide unit is very easy to synthesise, thus, hydrazide can be a promising anchoring group for DSSCs.
Crystal Growth & Design | 2017
Shuguang Chen; Zhen-Zhen Shi; Ling Qin; Hai-Lang Jia; He-Gen Zheng
Crystal Growth & Design | 2016
Zhen-Zhen Shi; Zhao-Rui Pan; Hai-Lang Jia; Shuguang Chen; Ling Qin; He-Gen Zheng
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Nanjing University of Information Science and Technology
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