The Synthesis of Nb-doped TiO2 Nanoparticles for Improved-Performance Dye Sensitized Solar Cells

Su, Haijun; Huang, Yu-Ting; Chang, Yu Shan; Zhai, Peng; Hau, Nga Yu; Cheung, Peter Chun Hin; Yeh, Wei‐Ting; Wei, Tzu‐Chien; Feng, Shien-Ping

doi:10.1016/j.electacta.2015.09.072

Cited by 92 publications

(36 citation statements)

References 29 publications

(40 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar effect of different oxide additives on the TiO2 phase transformation was reported by Yanagida et al [19]. In addition, the diffraction peaks shifted to lower θ values with increasing Nb content as a result of the larger radius of Nb 5+ (0.64 Å) compared to that of Ti 4+ (0.61 Å) [15], in accordance with the Bragg equation: λ = 2dsinθ (Figure 1b). (Figure 2a).…”

Section: Structural Characterization Of Nb-doped Tiosupporting

confidence: 87%

“…The observed lowering of the CBM of the sample containing 1.5 mol % and 3.0 mol % Nb due to donor levels induced by these dopants [18] is attributable to higher electron transitions between the Nb-doped TiO2 electrode and the anchoring TCNQ. On the other hand, the CBM for the sample containing 5.0 mol % Nb exhibited a large offset between its CBM energy and EF, compared to the undoped TiO2, due to intra-band transport [15].…”

Section: Optical Properties Of Nb-doped Tiomentioning

confidence: 90%

“…The Nb 3d3/2 and 3d5/2 peaks are located at binding energies of 209 and 206 eV, respectively. Nbdoping also caused the Ti 2p1/2 and 2p3/2 peaks to shift slightly toward higher binding energies, which is attributable to the higher electronegativity of Nb (1.6) compared to that of Ti (1.54) ( Figure 2b) [15]. The peaks in the O 1s spectra correspond to Ti 4+ -O bonds; the positions of these peaks show similar trends to those observed for Ti due to increases in both lattice oxygen and Nb 5+ -O bonds in these samples.…”

Section: Structural Characterization Of Nb-doped Tiomentioning

confidence: 99%

“…Among n-type-doped TiO 2 systems, Nb-doped TiO 2 photoanodes have been studied to improve electron conductance and injection because Nb has one more electron than Ti (IV) [12][13][14][15][16][17][18]. Recently, Lin et al reported the influence of TiO 2 doped with Group V-b metal atoms on the photovoltaic performance of dye-sensitized solar cells [18].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Improving Interfacial Charge-Transfer Transitions in Nb-Doped TiO2 Electrodes with 7,7,8,8-Tetracyanoquinodimethane

et al. 2018

View full text Add to dashboard Cite

Interfacial charge-transfer (ICT) transitions involved in charge-separation mechanisms are expected to enable efficient photovoltaic conversions through one-step charge-separation processes. With this in mind, the charge-transfer complex fabricated from TiO2 nanoparticles and 7,7,8,8-tetracyanoquinodimethane (TCNQ) has been applied to dye-sensitized solar cells. However, rapid carrier recombination from the conduction band of TiO2 to the highest occupied molecular orbital (HOMO) of TCNQ remains a major issue for this complex. In this study, to inhibit surface-complex recombinations, we prepared Nb-doped TiO2 nanoparticles with different atomic ratios for enhanced electron transport. To investigate the effects of doping on electron injection through ICT transitions, these materials were examined as photoelectrodes. When TiO2 was doped with 1.5 mol % Nb, the Fermi level of the TiO2 electrode shifted toward the conduction band minimum, which improved electron back-contact toward the HOMO of TCNQ. The enhancement in electron transport led to increases in both short circuit current and open circuit voltage, resulting in a slight (1.1% to 1.3%) improvement in photovoltaic conversion efficiency compared to undoped TiO2. Such control of electron transport within the photoelectrode is attributed to improvements in electron injection through ICT transitions.

show abstract

Section: Structural Characterization Of Nb-doped Tiosupporting

confidence: 87%

Section: Optical Properties Of Nb-doped Tiomentioning

confidence: 90%

Section: Structural Characterization Of Nb-doped Tiomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improving Interfacial Charge-Transfer Transitions in Nb-Doped TiO2 Electrodes with 7,7,8,8-Tetracyanoquinodimethane

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Recently, we reported a synthesis of TiO 2 nanoparticles which can be effectively applied to DSSC photoelectrode by wet coating [5,6]. By doping Nb or W within TiO 2 lattices, it is reported that the optical and electronic properties can be further improved while preserving the original crystalline structure owing to similar ionic sizes of Nb and Ti [7][8][9][10][11][12]. The subsequent increase in electron-transport ability elevates current density, finally improving the efficiency of solar cell.…”

Section: Introductionmentioning

confidence: 97%

Inverse opal photoelectrode of Nb-doped TiO2 nanoparticles for dye-sensitized solar cell

et al. 2016

View full text Add to dashboard Cite

In this study, Nb-doped TiO 2 nanoparticles were prepared by solution synthesis, and utilized as photoelectrode for dye-sensitized solar cell aiming to obtain better photon-to-current conversion efficiency. Nb doping was carried out using two different Nb precursors, and subsequent hydrothermal treatment resulted in the size-controlled (*10 nm) Nb-doped TiO 2 nanoparticles with typical ellipsoidal shapes and anatase morphologies. It was observed that NbCl 2 precursor resulted in more uniform particle size, while Nb oxalate resulted in relatively broader particle size distributions and higher aspect ratio ellipsoid. Using these nanoparticles, 10 lm-thick porous inverse opal (IO) photoelectrodes were fabricated by coating the mixed aqueous dispersions of Nb-TiO 2 nanoparticles and polystyrene particles of 270 nm diameter on conductive glass followed by thermal sintering. DSSC single cell performance tests revealed that a photoelectrode from 2 mol% Nb-TiO 2 obtained from NbCl 2 exhibited 20 % enhancement for solar cell efficiency compared to bare TiO 2 IO.Electronic supplementary material The online version of this article (

show abstract

Porous‐Alumina‐Assisted Growth of Nanostructured Anodic Films on Ti−Nb Alloys

et al. 2018

View full text Add to dashboard Cite

Porous-anodic-alumina (PAA)-assisted anodizing is employed, for the first time, for growing arrays of oxide nanocolumns on TiÀNb alloy films with up to 58 at% Nb. Beyond about 24 at% Nb in the alloy, the system allows for high formation potentials of 250-420 V, giving columns that are 500-700 nm long, which are 100 % stable during the PAA etch. The stability worsens when lowering the Nb content in the alloy, owing to contamination of the column roots by alumina, which arises from the amorphous-to-crystalline transition of the anodic oxide, oxygen evolution, formation of O 2 -filled nanobubbles within the roots, and development of bigger voids. The voids force the roots to regrow and spread laterally along with anodizing the surrounding Al residues, which increases alumina content in the titania-based nanoroots. The incorporation of sufficient amounts of Nb 2 O 5 in the anodic TiO 2 hinders oxide crystallization and lowers alumina content in the roots, which stabilizes the columns. The two oxides are distributed uniformly along the columns, indicating comparable migration rates of Ti 4 + and Nb 5 + ions in the mixed anodic oxide. This uniform distribution, combined with possibly mixing the oxides at atomic level, is expected to narrow the band gap of the material, which is of vast importance for solar energy conversion applications.[a] Dr.

show abstract

The Synthesis of Nb-doped TiO2 Nanoparticles for Improved-Performance Dye Sensitized Solar Cells

Cited by 92 publications

References 29 publications

Improving Interfacial Charge-Transfer Transitions in Nb-Doped TiO2 Electrodes with 7,7,8,8-Tetracyanoquinodimethane

Improving Interfacial Charge-Transfer Transitions in Nb-Doped TiO2 Electrodes with 7,7,8,8-Tetracyanoquinodimethane

Inverse opal photoelectrode of Nb-doped TiO2 nanoparticles for dye-sensitized solar cell

Porous‐Alumina‐Assisted Growth of Nanostructured Anodic Films on Ti−Nb Alloys

Contact Info

Product

Resources

About