Zinc-doped SnO₂ nanocrystals as photoanode materials for highly efficient dye-sensitized solar cells

Abstract

Zn-doped SnO 2 nanocrystals were successfully synthesized by a simple hydrothermal method. It is found that Zn doping into SnO 2 can induce a negative shift in the flat-band potential (V FB ) and increase the isoelectric point. As a result, dye-sensitized solar cells (DSCs) based on Zn-doped SnO 2 nanocrystal photoanodes exhibit longer electron lifetimes and higher dye loading compared to undoped SnO 2 based DSCs. The overall power conversion efficiency (h) of the optimized Zn-doped SnO 2 based DSC reaches 4.18% and increases to 7.70% after the TiCl 4 treatment. More importantly, a remarkable h of 8.23% is achieved for DSCs based on a high-quality double-layer SnO 2 photoanode with the TiCl 4 treatment, to the best of our knowledge, which is so far the best reported efficiency for DSCs based on SnO 2 photoanodes. † Electronic supplementary information (ESI) available: The pH-dependent zeta-potential of the undoped and Zn-doped SnO 2 nanoparticles; J-V characteristics of the undoped and Zn-doped SnO 2 based cells measured in the dark; J-V characteristics of the undoped and Zn-doped SnO 2 based cells with the TiCl 4 treatment; comparison of the photovoltaic performance of the DSCs based on SnO 2 photoanodes with various morphologies; Plots of lifetime of photoinjected electrons in the DSCs based on undoped and Zn-doped SnO 2 photoanodes with TiCl 4 treatment as a function of charge; FESEM image of SnO 2 spheres. SeeFig. 3 XPS high-resolution spectra of undoped and Zn-doped SnO 2 nanoparticles: (a) Sn 3d, (b) O 1s, and (c) Zn 2p peaks.This journal is

Photocatalytic Self‐Doped SnO2−x Nanocrystals Drive Visible‐Light‐Responsive Color Switching

“…[7a,8] Moreover,t he oxygen vacancies in SnO 2-x NCs can act as effective SEDs to scavenge photogenerated holes during illumination, enabling color switching of redox dyes.I nterestingly,t he O1 st ransition peak also shifted 0.2 eV (from 530.2 to 530.0 eV) upon self-doping of Sn 2+ (Figure 1d), which is similar to what was observed for previous transition metal-doped SnO 2 nanomaterials. [9] TheC peak located at 284.2 eV in both samples is probably due to surface-modified ligands and/or residual solvent (Figure S3 b). TheF TIR spectra clearly show hydroxy groups on SnO 2Àx NCs,w hich enable their high colloidal stability in water ( Figure S5).…”

“…[7] Thef ormation of oxygen vacancies is thought to give rise to shallow donor levels near the conduction band, enhancing the absorption in the visible light region. [9] TheC peak located at 284.2 eV in both samples is probably due to surface-modified ligands and/or residual solvent (Figure S3 b). [9] TheC peak located at 284.2 eV in both samples is probably due to surface-modified ligands and/or residual solvent (Figure S3 b).…”

Highlights on advances in SnO2 quantum dots: insights into synthesis strategies, modifications and applications

“…Tin dioxide (SnO 2 ), a kind of n-type semiconductor with wide-band-gap (E g = 3.64 eV at 300 K), has very wide applications in the fields of gas sensors [1][2][3][4][5][6][7][8][9][10], lithium-ion batteries (LIBs) [11,12], photocatalytic degradations [13,14] and dye-sensitized solar cells (DSSCs) [15][16][17][18][19], photodetectors [20] and heterojunction diode [21]. The wide applications of SnO 2 are greatly benefited from the synthesis methods in its nanostructured materials with different sizes and novel morphologies.…”

Surface defect engineering: gigantic enhancement in the optical and gas detection ability of metal oxide sensor

“…Besides, SnO 2 also can be used as photo-catalyst and solar-cell applications 55,[62][63][64] . In this research work, the Tin oxide nanomaterials were fabricated with different amounts of defect; and the devices were formed as Schottky gate device for the mechanism investigation.…”