Limits...
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.


SEM micrographs of (a) SnO2 nanoparticles; (b) ZnO commercial particles. (c) Cross sectional view of a bi-oxide photoanode. Scale bars: (a) and (b) 200 nm; (c) 5 μm. (d) XRD pattern of SnO2 nanoparticles. (e) Reflectance spectra of pure ZnO (grey line), pure SnO2 (dashed black line) and ZnO@SnO2 (solid black line) photoanodes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4588567&req=5

f1: SEM micrographs of (a) SnO2 nanoparticles; (b) ZnO commercial particles. (c) Cross sectional view of a bi-oxide photoanode. Scale bars: (a) and (b) 200 nm; (c) 5 μm. (d) XRD pattern of SnO2 nanoparticles. (e) Reflectance spectra of pure ZnO (grey line), pure SnO2 (dashed black line) and ZnO@SnO2 (solid black line) photoanodes.

Mentions: Figure 1 shows the SEM analysis of the metal oxide structures applied as photoanodes in this work. SnO2 NPs constitute a compact network after annealing characterized by homogenous particles (Fig. 1a). The GIXRD patter (Fig. 1d) reveals a good crystallinity of SnO2 NPs with crystallite size of 21 nm in accordance with SEM evaluation. On the other hand, commercially available ZnO structures are applied as capping layer, which are polydispersed in both sizes and shapes (Fig. 1b, aggregate size in the range 20 to 500 nm), thus acting as scattering centers for light26. Cross section SEM analysis clearly shows the bi-layered composition of the proposed photoanode architecture: SnO2 forms a quite compact scaffold, on top of which a more porous layer of ZnO is lying.


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)

SEM micrographs of (a) SnO2 nanoparticles; (b) ZnO commercial particles. (c) Cross sectional view of a bi-oxide photoanode. Scale bars: (a) and (b) 200 nm; (c) 5 μm. (d) XRD pattern of SnO2 nanoparticles. (e) Reflectance spectra of pure ZnO (grey line), pure SnO2 (dashed black line) and ZnO@SnO2 (solid black line) photoanodes.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1: SEM micrographs of (a) SnO2 nanoparticles; (b) ZnO commercial particles. (c) Cross sectional view of a bi-oxide photoanode. Scale bars: (a) and (b) 200 nm; (c) 5 μm. (d) XRD pattern of SnO2 nanoparticles. (e) Reflectance spectra of pure ZnO (grey line), pure SnO2 (dashed black line) and ZnO@SnO2 (solid black line) photoanodes.
Mentions: Figure 1 shows the SEM analysis of the metal oxide structures applied as photoanodes in this work. SnO2 NPs constitute a compact network after annealing characterized by homogenous particles (Fig. 1a). The GIXRD patter (Fig. 1d) reveals a good crystallinity of SnO2 NPs with crystallite size of 21 nm in accordance with SEM evaluation. On the other hand, commercially available ZnO structures are applied as capping layer, which are polydispersed in both sizes and shapes (Fig. 1b, aggregate size in the range 20 to 500 nm), thus acting as scattering centers for light26. Cross section SEM analysis clearly shows the bi-layered composition of the proposed photoanode architecture: SnO2 forms a quite compact scaffold, on top of which a more porous layer of ZnO is lying.

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.