Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy
Photoconversion processes such as electron injection (photooxidation) and dye regeneration (reduction) in dye-sensitized solar cells (DSSCs) occur at considerably inhomogeneous semiconductor/dye/electrolyte interfaces, implying a very high heterogeneity of interfacial photoconversion kinetics. Herei...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-04-01
|
| Series: | Energies |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1073/13/8/1866 |
| _version_ | 1797570906543882240 |
|---|---|
| author | Masaaki Mitsui Kyosuke Mori Reina Kobayashi |
| author_facet | Masaaki Mitsui Kyosuke Mori Reina Kobayashi |
| author_sort | Masaaki Mitsui |
| collection | DOAJ |
| description | Photoconversion processes such as electron injection (photooxidation) and dye regeneration (reduction) in dye-sensitized solar cells (DSSCs) occur at considerably inhomogeneous semiconductor/dye/electrolyte interfaces, implying a very high heterogeneity of interfacial photoconversion kinetics. Herein, we present a temporally and spatially resolved investigation of DSSCs comprising a cover glass photoanode with a 100-nm thick TiO<sub>2</sub> layer loaded with the metal-free organic dye sensitizer MK-2, which is performed by employing laser scanning microscopy (LSM) for the simultaneous measurement of the photocurrent (PC) and photoluminescence (PL) of DSSCs under short-circuit conditions. Analysis of PL decay curves and the excitation rate dependences of PC and PL obtained for local (or submicrometric) areas of the MK-2-DSSC allows disclosing and quantifying three types of dyes coexisting in the DSSCs: (i) a dye that only generates PC (“PC-dye,” 75% of total dye molecules in the DSSC), (ii) a dye that generates both PC and PL (“PCPL-dye,” 20%), and (iii) a dye that only generates PL (“PL-dye,” 5%). Considering recent theoretical reports on cyanoacrylic dyes, we propose that the PC-dye and the PCPL-dye are covalently bound on a TiO<sub>2</sub> surface with different adsorption modes (presumably bidentate and tridentate bridging configurations), whereas the PL-dye is noncovalently trapped within a mesoporous TiO<sub>2</sub> film. |
| first_indexed | 2024-03-10T20:32:05Z |
| format | Article |
| id | doaj.art-959df468157947b691718f45d9096cd6 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T20:32:05Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-959df468157947b691718f45d9096cd62023-11-19T21:20:51ZengMDPI AGEnergies1996-10732020-04-01138186610.3390/en13081866Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning MicroscopyMasaaki Mitsui0Kyosuke Mori1Reina Kobayashi2Department of Chemistry, College of Science, Rikkyo University, 3-34-1, Nishiikebukuro, Toshima-ku, Tokyo 171-8501, JapanDepartment of Chemistry, College of Science, Rikkyo University, 3-34-1, Nishiikebukuro, Toshima-ku, Tokyo 171-8501, JapanDepartment of Chemistry, College of Science, Rikkyo University, 3-34-1, Nishiikebukuro, Toshima-ku, Tokyo 171-8501, JapanPhotoconversion processes such as electron injection (photooxidation) and dye regeneration (reduction) in dye-sensitized solar cells (DSSCs) occur at considerably inhomogeneous semiconductor/dye/electrolyte interfaces, implying a very high heterogeneity of interfacial photoconversion kinetics. Herein, we present a temporally and spatially resolved investigation of DSSCs comprising a cover glass photoanode with a 100-nm thick TiO<sub>2</sub> layer loaded with the metal-free organic dye sensitizer MK-2, which is performed by employing laser scanning microscopy (LSM) for the simultaneous measurement of the photocurrent (PC) and photoluminescence (PL) of DSSCs under short-circuit conditions. Analysis of PL decay curves and the excitation rate dependences of PC and PL obtained for local (or submicrometric) areas of the MK-2-DSSC allows disclosing and quantifying three types of dyes coexisting in the DSSCs: (i) a dye that only generates PC (“PC-dye,” 75% of total dye molecules in the DSSC), (ii) a dye that generates both PC and PL (“PCPL-dye,” 20%), and (iii) a dye that only generates PL (“PL-dye,” 5%). Considering recent theoretical reports on cyanoacrylic dyes, we propose that the PC-dye and the PCPL-dye are covalently bound on a TiO<sub>2</sub> surface with different adsorption modes (presumably bidentate and tridentate bridging configurations), whereas the PL-dye is noncovalently trapped within a mesoporous TiO<sub>2</sub> film.https://www.mdpi.com/1996-1073/13/8/1866dye-sensitized solar cellsphotocurrentphotoluminescencemicroscopy |
| spellingShingle | Masaaki Mitsui Kyosuke Mori Reina Kobayashi Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy Energies dye-sensitized solar cells photocurrent photoluminescence microscopy |
| title | Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy |
| title_full | Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy |
| title_fullStr | Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy |
| title_full_unstemmed | Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy |
| title_short | Quantification of Dyes Generating Photocurrent and/or Photoluminescence in Dye-Sensitized Solar Cells Using Laser Scanning Microscopy |
| title_sort | quantification of dyes generating photocurrent and or photoluminescence in dye sensitized solar cells using laser scanning microscopy |
| topic | dye-sensitized solar cells photocurrent photoluminescence microscopy |
| url | https://www.mdpi.com/1996-1073/13/8/1866 |
| work_keys_str_mv | AT masaakimitsui quantificationofdyesgeneratingphotocurrentandorphotoluminescenceindyesensitizedsolarcellsusinglaserscanningmicroscopy AT kyosukemori quantificationofdyesgeneratingphotocurrentandorphotoluminescenceindyesensitizedsolarcellsusinglaserscanningmicroscopy AT reinakobayashi quantificationofdyesgeneratingphotocurrentandorphotoluminescenceindyesensitizedsolarcellsusinglaserscanningmicroscopy |