Fabrication of polythiophene–TiO2 heterojunction solar cells coupled with upconversion nanoparticles

Abstract

We introduce lanthanide-doped LiYF 4 upconversion nanoparticles into TiO 2 film and use the obtained composite film to photocatalyze the polymerization of thiophene, developing a polythiophene-TiO 2 heterojunction coupled with upconversion nanoparticles. The upconversion nanoparticles, which are capable of converting long-wavelength photons into shorter ones, aim to broaden the light-harvesting of the heterojunction films. Solar cells are fabricated from the heterojunction films coupled with different contents of upconversion nanoparticles, and measured in respect to the incident photon-electron conversion efficiencies and the current density-voltage curves. It is revealed that the upconversion nanoparticles enable the devices to utilize the long-wavelength photons, and thus, the photovoltaic performances are enhanced. Moreover, by employing Raman spectroscopy, we monitor the process of polymerization on the TiO 2 substrate and put deep insight into the interfacial interaction of the heterojunction.

Influence of carbon atmosphere on surface morphology and photocatalytic activity of TiO2 coatings by multi-heat treatment

“…The difference in color during subsequent oxidation among M10-O, M10-O 0 -O and M10-C-O is related to surface morphology and thickness of the crystal coatings [23][24][25]. The color change during reduction indicates that reduction affects the formation of oxygen vacancies, which produce the color centers of Ti 3? in the TiO 2 [26,27], and this is similar to these results obtained by hydrogen treatment [7,20].…”

“…However, the application of TiO 2 has been limited to the ultraviolet (UV) range due to its wider band gap, and fast electronhole recombination due to a high density of trap stats [6][7][8]. Several reviews highlight the advances in the field of enhancing the visible-light active TiO 2 photocatalysts, mainly by sensitization with small band gap semiconductors, and narrowing the band gap via elemental doping [9][10][11][12][13].…”

BiOCl/ultrathin polyaniline core/shell nanosheets with a sensitization mechanism for efficient visible-light-driven photocatalysis

“…Then, the BiOCl can use the captured electrons to reduce O 2 into ·O 2 − , a highly active oxidant for degrading RhB. As there are holes left in the HOMO of PANI, the OH − can react with them to produce ·OH, also contributing to the degradation of RhB [42,43]. Besides, it is possible that the holes in the HOMO of PANI can directly degrade RhB.…”

Upconversion 3D Printed Composite with Multifunctional Applications for Tissue Engineering and Photodynamic Therapy

“…Lanthanide (Ln 3+ )-doped upconversion nanoparticles (UCNPs) have emerged as an attractive luminescent material due to their excellent optical properties related to their ability to convert low-energy near-infrared (NIR) light into high-energy UV or visible light in a process that involves the sequential absorption of photons. 1 Application trends of UNCPs in literature involve analytes detection, 2 nanothermometry, 3 photovoltaic cell, 4 and photocatalytic systems. 5 Concerning the biomedical field, several bioapplications were reported in bioimaging platforms, 6 thermal cellular imaging, 7 bioassay, 8 biosensing, 9 disease detection, 10 drug delivery systems, 11 light activated therapies, 12 and theranostic platforms.…”