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ZnO@SnO2 engineered composite photoanodes for dye sensitized solar cells.

Milan R, Selopal GS, Epifani M, Natile MM, Sberveglieri G, Vomiero A, Concina I - Sci Rep (2015)

Bottom Line: Bi-oxide photoanodes performed much better in terms of photoconversion efficiency (PCE) (4.96%) compared to bare SnO2 (1.20%) and ZnO (1.03%).Synergistic cooperation is effective for both open circuit voltage and photocurrent density: enhanced values were indeed recorded for the layered photoanode as compared with bare oxides (Voc enhanced from 0.39 V in case of bare SnO2 to 0.60 V and Jsc improved from 2.58 mA/cm(2) pertaining to single ZnO to 14.8 mA/cm(2)).Compared with previously reported results, this study testifies how a simple electrode design is powerful in enhancing the functional performances of the final device.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, University of Brescia - via Valotti 9, 25133 Brescia, Italy.

ABSTRACT
Layered multi-oxide concept was applied for fabrication of photoanodes for dye-sensitized solar cells based on ZnO and SnO2, capitalizing on the beneficial properties of each oxide. The effect of different combinations of ZnO@SnO2 layers was investigated, aimed at exploiting the high carrier mobility provided by the ZnO and the higher stability under UV irradiation pledged by SnO2. Bi-oxide photoanodes performed much better in terms of photoconversion efficiency (PCE) (4.96%) compared to bare SnO2 (1.20%) and ZnO (1.03%). Synergistic cooperation is effective for both open circuit voltage and photocurrent density: enhanced values were indeed recorded for the layered photoanode as compared with bare oxides (Voc enhanced from 0.39 V in case of bare SnO2 to 0.60 V and Jsc improved from 2.58 mA/cm(2) pertaining to single ZnO to 14.8 mA/cm(2)). Improved functional performances of the layered network were ascribable to the optimization of both high chemical capacitance (provided by the SnO2) and low recombination resistance (guaranteed by ZnO) and inhibition of back electron transfer from the SnO2 conduction band to the oxidized species of the electrolyte. Compared with previously reported results, this study testifies how a simple electrode design is powerful in enhancing the functional performances of the final device.

No MeSH data available.


(a) Nyquist diagrams of cells at forwarded bias of 600 mV in the dark. (b) Recombination resistance between the semiconductors metal oxides and the acceptor species in the electrolyte (c) Chemical capacitance Cu and (d) electron lifetime t as function of bias. Black line: 1@5 ZnO@SnO2; blue line: 2@4 ZnO@SnO2; grey line: ZnO; light grey line: SnO2.
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f7: (a) Nyquist diagrams of cells at forwarded bias of 600 mV in the dark. (b) Recombination resistance between the semiconductors metal oxides and the acceptor species in the electrolyte (c) Chemical capacitance Cu and (d) electron lifetime t as function of bias. Black line: 1@5 ZnO@SnO2; blue line: 2@4 ZnO@SnO2; grey line: ZnO; light grey line: SnO2.

Mentions: Main task of EIS analysis was the study of two critical parameters: the chemical capacitance (Cμ) and the recombination resistance (RREC). Cμ relates to modified electron density of the semiconductor metal oxide as a function of the Fermi level, whereas RREC estimates the recombination between electrons in the photoanode and holes in the electrolyte. These parameters are calculated by using proper equivalent circuit32 to fit the experimental data, reported as Nyquist diagram in Fig. 7a.


ZnO@SnO2 engineered composite photoanodes for dye sensitized solar cells.

Milan R, Selopal GS, Epifani M, Natile MM, Sberveglieri G, Vomiero A, Concina I - Sci Rep (2015)

(a) Nyquist diagrams of cells at forwarded bias of 600 mV in the dark. (b) Recombination resistance between the semiconductors metal oxides and the acceptor species in the electrolyte (c) Chemical capacitance Cu and (d) electron lifetime t as function of bias. Black line: 1@5 ZnO@SnO2; blue line: 2@4 ZnO@SnO2; grey line: ZnO; light grey line: SnO2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588567&req=5

f7: (a) Nyquist diagrams of cells at forwarded bias of 600 mV in the dark. (b) Recombination resistance between the semiconductors metal oxides and the acceptor species in the electrolyte (c) Chemical capacitance Cu and (d) electron lifetime t as function of bias. Black line: 1@5 ZnO@SnO2; blue line: 2@4 ZnO@SnO2; grey line: ZnO; light grey line: SnO2.
Mentions: Main task of EIS analysis was the study of two critical parameters: the chemical capacitance (Cμ) and the recombination resistance (RREC). Cμ relates to modified electron density of the semiconductor metal oxide as a function of the Fermi level, whereas RREC estimates the recombination between electrons in the photoanode and holes in the electrolyte. These parameters are calculated by using proper equivalent circuit32 to fit the experimental data, reported as Nyquist diagram in Fig. 7a.

Bottom Line: Bi-oxide photoanodes performed much better in terms of photoconversion efficiency (PCE) (4.96%) compared to bare SnO2 (1.20%) and ZnO (1.03%).Synergistic cooperation is effective for both open circuit voltage and photocurrent density: enhanced values were indeed recorded for the layered photoanode as compared with bare oxides (Voc enhanced from 0.39 V in case of bare SnO2 to 0.60 V and Jsc improved from 2.58 mA/cm(2) pertaining to single ZnO to 14.8 mA/cm(2)).Compared with previously reported results, this study testifies how a simple electrode design is powerful in enhancing the functional performances of the final device.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, University of Brescia - via Valotti 9, 25133 Brescia, Italy.

ABSTRACT
Layered multi-oxide concept was applied for fabrication of photoanodes for dye-sensitized solar cells based on ZnO and SnO2, capitalizing on the beneficial properties of each oxide. The effect of different combinations of ZnO@SnO2 layers was investigated, aimed at exploiting the high carrier mobility provided by the ZnO and the higher stability under UV irradiation pledged by SnO2. Bi-oxide photoanodes performed much better in terms of photoconversion efficiency (PCE) (4.96%) compared to bare SnO2 (1.20%) and ZnO (1.03%). Synergistic cooperation is effective for both open circuit voltage and photocurrent density: enhanced values were indeed recorded for the layered photoanode as compared with bare oxides (Voc enhanced from 0.39 V in case of bare SnO2 to 0.60 V and Jsc improved from 2.58 mA/cm(2) pertaining to single ZnO to 14.8 mA/cm(2)). Improved functional performances of the layered network were ascribable to the optimization of both high chemical capacitance (provided by the SnO2) and low recombination resistance (guaranteed by ZnO) and inhibition of back electron transfer from the SnO2 conduction band to the oxidized species of the electrolyte. Compared with previously reported results, this study testifies how a simple electrode design is powerful in enhancing the functional performances of the final device.

No MeSH data available.