記述言語：英語   出版者・発行元：ACS Applied Materials Interfaces  

4-(1,3-Dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)-N,N-dimethylaniline (N-DMBI) was employed as an n-dopant for single-walled carbon nanotube (SWCNT) thin films, enabling the fabrication of an inverted perovskite solar cell with the structure ITO/hole transport layer (HTL)/CH3NH3PbI3/6,6-phenyl-C61-butyric acid methyl ester (PCBM)/N,N'-bis[3-(dimethylamino)propyl]perylene-3,4,9,10-tetracarboxylic diimide (PDIN)/N-DMBI-doped SWCNT. This structure eliminates the need for conventional metallic back electrodes. When poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) was used as HTL, a power conversion efficiency of 9.9% was achieved. Substituting PEDOT:PSS with poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) further improved the PCE to 10.1%. The long-term stability of the device was evaluated under a nitrogen atmosphere for 50 days. The PCE of devices with Ag electrodes decreased by 50%, whereas those with SWCNT electrodes retained 90% of their initial performance. N-DMBI doping of SWCNT thin films reduced the sheet resistance from 73.4 Ω/sq to 32.6 Ω/sq and shifted the ionization potential to a shallower value. Furthermore, the Seebeck coefficient changed from +65.7 μV/K to -22.5 μV/K, confirming the successful formation of n-type SWCNTs. X-ray photoelectron spectroscopy revealed that doping with N-DMBI or PDIN effectively removed oxygen and water molecules from the SWCNT surface. This study introduced PDIN as an interfacial layer between PCBM and the SWCNTs, preventing direct contact between these layers. This structure exhibited J-V characteristics with reduced losses in open-circuit voltage and fill factor by suppressing carrier traps.

DOI： 10.1021/acsami.5c18054

Web of Science

Scopus

PubMed

DOI： 10.1039/d5ta06786c

Web of Science

出版者・発行元：Japanese Journal of Applied Physics Part 1 Regular Papers and Short Notes and Review Papers  

To fabricate a uniform spray-coated single-walled carbon nanotubes (wet-CNT) film as a replacement for an indium tin oxide substrate, a combination of ultrasonic treatment, centrifugation, and filtration was employed and systematically evaluated. Filtration effectively reduced carrier trap density, enabling to the fabrication of inverted perovskite solar cells with a glass/CNT/PEDOT:PSS/CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf>/C<inf>60</inf>/Ag structure. Furthermore, the wet-CNT film with vapor-transferred HNO<inf>3</inf> doping as a p-dopant, a significantly deeper energy level shift compared to the vapor deposition process based carbon nanotube (dry-CNT) film, likely due to water molecules on the CNT surface facilitating oxidation through interactions with HNO<inf>3</inf>. On the other hand, when AuCl<inf>3</inf>/IPA was employed as a dopant, the dry-CNT film, exhibited a greater energy level shift, attributed to the hydrophobic surface retaining Au³⁺ ions more effectively.

DOI： 10.35848/1347-4065/adc463

Open Access

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Scopus

記述言語：英語   出版者・発行元：Molecules  

Perovskite solar cell (PSC) technology holds great promise with continuously improving power conversion efficiency; however, the use of metal electrodes hinders its commercialization and the development of tandem designs. Although single-walled carbon nanotubes (SWCNTs), as one-dimensional materials, have the potential to replace metal electrodes in PSCs, their poor conductivity still limits their application. In this study, the near-infrared (NIR)-absorbing anionic heptamethine cyanine dye-doped SWCNTs functioned in a dual role as an efficient charge-selective layer and electrode in PSCs. Benefiting from the improvement in conductivities and matched energy level of doped-SWCNT, the dual-role SWCNT electrodes applied to PSCs achieved a better performance than the undoped PSCs with a higher short circuit current (J<inf>SC</inf>) and fill factor (FF).

DOI： 10.3390/molecules30010060

Open Access

Web of Science

Scopus

PubMed

記述言語：英語   出版者・発行元：Photochem  

Perovskite solar cells with an indium tin oxide (ITO)/SnO<inf>2</inf>/CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3</inf>/Spiro-OMeTAD/2,2,2-trifluoroethanol (TFE) doped single-walled carbon nanotube (SWCNT) structure were developed by dropping TFE onto SWCNTs, which replaced the metal back electrode, and a conversion efficiency of 14.1% was achieved. Traditionally, acidic doping of the back electrode, SWCNT, has been challenging due to the potential damage it may cause to the perovskite layer. However, TFE has facilitated easy doping of SWCNT as the back electrode. The sheet resistance of the SWCNTs decreased and their ionization potential shifted to deeper levels, resulting in improved hole transport properties with a lower barrier to carrier transport. Furthermore, the Seebeck coefficient (S) increased from 34.5 μV/K to 73.1 μV/K when TFE was dropped instead of EtOH, indicating an enhancement in the behavior of p-type charge carriers. It was observed that hydrophilic substances adhered less to the SWCNT surface, and the formation of PbI<inf>2</inf> was suppressed. These effects resulted in higher conversion efficiency and improved solar cell performance. Furthermore, the decrease in conversion efficiency after 260 days was suppressed, showing improved durability. The study suggests that combining SWCNTs and TFEs improves solar cell performance and stability.

DOI： 10.3390/photochem4030019

Open Access

Web of Science

Scopus

総ページ数：194   担当ページ：27-35   記述言語：日本語 著書種別：学術書

開催年月日： 2024年8月

記述言語：英語   会議種別：口頭発表（一般）  

国名：大韓民国  

開催年月日： 2025年3月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：関西大学千里山キャンパス   国名：日本国  

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：あいちウインク   国名：日本国  

記述言語：英語   会議種別：シンポジウム・ワークショップ パネル（指名）  

開催地：Nagoya University   国名：日本国