Enhanced power conversion efficiency of dye-sensitized solar cells by band edge shift of TiO2 photoanode

Hye Kyeong Sung; Yeonju Lee; Wook Hyun Kim; Sang Ju Lee; Shi Joon Sung; Dae Hwan Kim; Yoon Soo Han

doi:10.3390/molecules25071502

Enhanced power conversion efficiency of dye-sensitized solar cells by band edge shift of TiO₂ photoanode

Hye Kyeong Sung, Yeonju Lee, Wook Hyun Kim, Sang Ju Lee, Shi Joon Sung, Dae Hwan Kim, Yoon Soo Han

Division of Energy Techonology

Research output: Contribution to journal › Article › peer-review

19 Scopus citations

Abstract

By simple soaking titanium dioxide (TiO₂) films in an aqueous Na₂S solution, we could prepare surface-modified photoanodes for application to dye-sensitized solar cells (DSSCs). An improvement in both the open-circuit voltage (V_oc) and the fill factor (FF) was observed in the DSSC with the 5 min-soaked photoanode, compared with those of the control cell without any modification. The UV-visible absorbance spectra, UPS valence band spectra, and dark current measurements revealed that the Na₂S modification led to the formation of anions on the TiO₂ surface, and thereby shifted the conduction band edge of TiO₂ in the negative (upward) direction, inducing an increase of 29 mV in the V_oc. It was also found that the increased FF value in the surface-treated device was attributed to an elevation in the shunt resistance.

Original language	English
Article number	1502
Journal	Molecules
Volume	25
Issue number	7
DOIs	https://doi.org/10.3390/molecules25071502
State	Published - 2020

Bibliographical note

Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Keywords

Conduction band edge shift
Dye-sensitized solar cell
Sodium sulfide
Surface modification

Access to Document

10.3390/molecules25071502

Cite this

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title = "Enhanced power conversion efficiency of dye-sensitized solar cells by band edge shift of TiO2 photoanode",

abstract = "By simple soaking titanium dioxide (TiO2) films in an aqueous Na2S solution, we could prepare surface-modified photoanodes for application to dye-sensitized solar cells (DSSCs). An improvement in both the open-circuit voltage (Voc) and the fill factor (FF) was observed in the DSSC with the 5 min-soaked photoanode, compared with those of the control cell without any modification. The UV-visible absorbance spectra, UPS valence band spectra, and dark current measurements revealed that the Na2S modification led to the formation of anions on the TiO2 surface, and thereby shifted the conduction band edge of TiO2 in the negative (upward) direction, inducing an increase of 29 mV in the Voc. It was also found that the increased FF value in the surface-treated device was attributed to an elevation in the shunt resistance.",

keywords = "Conduction band edge shift, Dye-sensitized solar cell, Sodium sulfide, Surface modification",

author = "Sung, \{Hye Kyeong\} and Yeonju Lee and Kim, \{Wook Hyun\} and Lee, \{Sang Ju\} and Sung, \{Shi Joon\} and Kim, \{Dae Hwan\} and Han, \{Yoon Soo\}",

note = "Publisher Copyright: {\textcopyright} 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).",

year = "2020",

doi = "10.3390/molecules25071502",

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T1 - Enhanced power conversion efficiency of dye-sensitized solar cells by band edge shift of TiO2 photoanode

AU - Sung, Hye Kyeong

AU - Lee, Yeonju

AU - Kim, Wook Hyun

AU - Lee, Sang Ju

AU - Sung, Shi Joon

AU - Kim, Dae Hwan

AU - Han, Yoon Soo

N1 - Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

PY - 2020

Y1 - 2020

N2 - By simple soaking titanium dioxide (TiO2) films in an aqueous Na2S solution, we could prepare surface-modified photoanodes for application to dye-sensitized solar cells (DSSCs). An improvement in both the open-circuit voltage (Voc) and the fill factor (FF) was observed in the DSSC with the 5 min-soaked photoanode, compared with those of the control cell without any modification. The UV-visible absorbance spectra, UPS valence band spectra, and dark current measurements revealed that the Na2S modification led to the formation of anions on the TiO2 surface, and thereby shifted the conduction band edge of TiO2 in the negative (upward) direction, inducing an increase of 29 mV in the Voc. It was also found that the increased FF value in the surface-treated device was attributed to an elevation in the shunt resistance.

AB - By simple soaking titanium dioxide (TiO2) films in an aqueous Na2S solution, we could prepare surface-modified photoanodes for application to dye-sensitized solar cells (DSSCs). An improvement in both the open-circuit voltage (Voc) and the fill factor (FF) was observed in the DSSC with the 5 min-soaked photoanode, compared with those of the control cell without any modification. The UV-visible absorbance spectra, UPS valence band spectra, and dark current measurements revealed that the Na2S modification led to the formation of anions on the TiO2 surface, and thereby shifted the conduction band edge of TiO2 in the negative (upward) direction, inducing an increase of 29 mV in the Voc. It was also found that the increased FF value in the surface-treated device was attributed to an elevation in the shunt resistance.

KW - Conduction band edge shift

KW - Dye-sensitized solar cell

KW - Sodium sulfide

KW - Surface modification

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