| 1. |
- Cai, Bin, et al.
(författare)
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Boosting the power conversion efficiency of perovskite solar cells to 17.7% with an indolo[3,2-b]carbazole dopant-free hole transporting material by improving its spatial configuration
- 2019
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 7:24, s. 14835-14841
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Tidskriftsartikel (refereegranskat)abstract
- The development of facilely synthesized, dopant-free hole-transporting materials (HTMs) with high efficiency is of great significance for the potential application of perovskite solar cells (PSCs). Herein, we report two novel indolo[3,2-b]carbazole (ICZ) based small molecules obtained via a three-step reaction in a high yield without using expensive catalysts, namely C201 and C202, and further apply them as dopant-free HTMs in PSCs. Compared with C201, C202 contains two additional biphenylamino groups to improve its spatial configuration. It is found that the interplay between the molecular geometry and the aggregation behavior can exert a great influence on the film formation property and thus on the device performance. Strikingly, the champion devices employing C202 as the HTM deliver a much higher PCE of up to 17.7%, which is substantially higher than that of devices containing C201 (8.7%) under 100 mW cm(-2) illumination (AM 1.5G). It is revealed that the C202 capping layer exhibits a more homogeneous and uniform surface morphology as compared to that of C201, which effectively reduces the charge recombination losses and facilitates charge extraction, leading to a much-enhanced photovoltaic performance. This is the first example of ICZ core-based small molecules as dopant-free HTMs in PSCs. Moreover, the PSCs containing C202 as the HTM also exhibited good long-term stability under ambient conditions (40% RH) as compared to devices with doped spiro-OMeTAD, due largely to the hydrophobic nature of C202 which prevented moisture from destroying the perovskite film. This work offers a new avenue for developing cost-effective and stable HTMs for PSCs and other optoelectronic devices.
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| 2. |
- Cheng, Ming, et al.
(författare)
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Molecular engineering of small molecules donor materials based on phenoxazine core unit for solution-processed organic solar cells
- 2014
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488. ; 2:27, s. 10465-10469
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Tidskriftsartikel (refereegranskat)abstract
- A D-pi-A type small molecule POZ4 and a A-pi-D-pi-A type small molecule POZ6, in which phenoxazine was used as the central building block and dicyanovinyl was employed as the electron-withdrawing end-group, have been designed and synthesized. Compared with D-pi-A type donor material POZ4, the donor material POZ6 with A-pi-D-pi-A configuration shows much wider response to solar light. An efficiency of 5.60% was obtained for the POZ6: PC71BM based solar cells, and the device fabricated with POZ6:PC71BM (1 : 1) showed a much better balanced hole and electron mobility of 2.24 x 10(-4) cm(2) V-1 s(-1) and 3.17 x 10(-4) cm(2) V-1 s(-1), respectively.
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| 3. |
- Jiang, Xiaoqing, et al.
(författare)
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A solution-processable copper(II) phthalocyanine derivative as a dopant-free hole-transporting material for efficient and stable carbon counter electrode-based perovskite solar cells
- 2017
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 5:34, s. 17862-17866
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Tidskriftsartikel (refereegranskat)abstract
- A solution-processable copper(II) phthalocyanine derivative coded as CuPc-TIPS has been synthesized and adopted as a hole-transporting material (HTM) in perovskite solar cells (PSCs), in combination with a mixed-ion perovskite absorber and a low-cost carbon cathode. Optimised PSC devices based on pristine CuPc-TIPS without any additives or dopants show a decent power conversion efficiency of 14.0% (measured at 100 mW cm(-2) illumination, AM 1.5G), together with a good long-termstability under ambient conditions. The present finding highlights the potential of solution-processed copper phthalocyanine derivative-based HTMs for the development of efficient and stable PSCs in the future.
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| 4. |
- Wang, Haoxin, et al.
(författare)
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One plus one greater than two : high-performance inverted planar perovskite solar cells based on a composite CuI/CuSCN hole-transporting layer
- 2018
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 6:43, s. 21435-21444
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Tidskriftsartikel (refereegranskat)abstract
- The low-cost and stable inorganic p-type semiconductor copper(i) iodide (CuI) is a promising hole-transporting layer (HTL) material for inverted planar perovskite solar cells (PSCs). However, the power conversion efficiencies (PCEs) of inverted planar PSCs based on CuI HTLs reported so far are not satisfactory and far behind those of their organic counterparts. Herein, we demonstrate a simple but effective approach to improve the performance of inverted planar PSCs based on the CuI HTL through the incorporation of copper thiocyanate (CuSCN) into the CuI HTL. As compared to pristine CuI, the introduction of CuSCN significantly improves the quality of the film, resulting in a smooth and uniform film while maintaining relatively high electrical conductivity. As a consequence, the champion device based on the composite CuI/CuSCN HTL affords an impressive PCE of 18.76% under full sun illumination (100 mW cm(-2), AM 1.5G), which is substantially higher than the corresponding values of the respective devices containing pristine CuI (14.53%) and CuSCN (16.66%). This value is one of the highest efficiencies reported thus far for CuI- and CuSCN-based HTLs in PSCs. This work demonstrates the great potential of low-temperature solution-processed CuI/CuSCN composites as hole-selective layers for low-cost and efficient PSCs as well as other optoelectronic devices.
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| 5. |
- Zhang, Fuguo, et al.
(författare)
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Engineering of hole-selective contact for low temperature-processed carbon counter electrodebased perovskite solar cells
- 2015
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 3:48, s. 24272-24280
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Tidskriftsartikel (refereegranskat)abstract
- A cost-effective and solution processable hole transport material (HTM), TPDI (5,10,15-triphenyl-5H-diindolo[3,2-a:3',2'-c]carbazole), was synthesized and explored as a hole selective contact material in low temperature (100 degrees C) and printable processed carbon counter electrode based perovskite solar cells (PSCs) for the first time. This material demonstrated excellent thermal stability, high hole mobility and appropriate energy level alignment with CH3NH3PbI3 and carbon, which make it a potentially excellent alternative interfacial material for PSCs. By interfacial engineering with doped TPDI, the energy barrier at the CH3NH3PbI3/carbon interface was efficiently eliminated. Dramatically enhanced power conversion efficiency (PCE) of 15.5% was afforded, which is comparable to or even better than that of the reference device with 2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) as HTM under equivalent conditions. Besides, TPDI can also function well in its pristine form although the efficiency (13.6%) obtained is slightly lower than that with the device containing doped TPDI as the HTM. Moreover, these newly integrated noble metal-free, vacuum-free and cost effective PSCs exhibited excellent durability during the long term stability measurements for 30 days. The remarkable performance as well as dramatically reduced fabrication cost demonstrated by integrating TPDI as the HTM and cost effective commercial carbon as the cathode revealed their great potential in the scalable and practical application of PSCs.
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| 6. |
- Zhao, Jianghua, et al.
(författare)
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Highly efficient iso-quinoline cationic organic dyes without vinyl groups for dye-sensitized solar cells
- 2013
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 1:7, s. 2441-2446
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Tidskriftsartikel (refereegranskat)abstract
- Four organic dyes without a vinyl group are synthesized and applied in dye-sensitized solar cells (DSSCs). The iso-quinoline cation is employed firstly as an electron acceptor in the dye molecular structure. The effect of different dye structures on the photo-electrochemical properties and the performance of the DSSCs are systematically studied. The photovoltaic performances of the DSSCs sensitized by the JH304 dye exhibit the best conversion efficiency of 7.3% (under standard AM 1.5G illumination (100 mW cm(-2))) with a short-circuit current density (J(sc)) of 14.4 mA cm(-2), an open-circuit voltage (V-oc) of 684 mV and a fill factor (ff) of 74.4%. In comparison, the device sensitized by the N719 dye shows an efficiency of 7.9%. The DSSC device sensitized by JH304 also exhibits excellent soaking stability under sunlight for 1000 h.
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