مقالات منتشر شده

امتیاز کاربران

Maryam Adineh, Pooya Tahay, Akram Shahrjerdi, Seyed Saeed Hoseini Davarani, Nasser Safari

The applications of electrochemically functionalized porphyrin have been considered in dye-sensitized solar cells (DSSCs). A porphyrin-catechol derivative has been electrochemically functionalized with a sulfur-contained, 2-mercaptobenzothiazole moiety and was tested as dye. Catechol moiety acts as the anchoring group in these types of dyes. The IPCE result confirmed that photocurrents for DSSCs based on porphyrin-catechol dyes are mainly generated by an indirect electron injection pathway (Type I mechanism). The cells made with this porphyrin were stable and showed no significant desorption of dye from the TiO₂ surface after days. Electrochemically functionalized porphyrin-catechol showed almost 100 % enhancement in efficiency compared to bare porphyrin-catechol. The effect of different additives on cell performance was also tested. Electrochemically functionalized porphyrin catechol, in the presence of chenodeoxycholic acid had a record performance with a conversion efficiency of 0.6 % under AM 1.5 irradiation.

Link: https://link.springer.com/article/10.1007/s13738-016-0850-x

امتیاز کاربران

Maryam Adineh,  Pooya Tahay, Mohsen Ameri,  Nasser Safari  and  Ezeddin Mohajerani

Herein we report the preparation and application of 4 different zinc(II) tetrakis(dihydroxyphenyl) porphyrins (ZnTDHPP) as the sensitizing dyes in dye-sensitized solar cells (DSSCs). The experimental results include solution and solid state UV-Vis data, steady state current–voltage characteristics, and our theoretical analysis comprised of density functional theory (DFT) and Langmuir isotherm adsorption formalism. The results show that the Zn tetrakis(2,3-dihydroxyphenyl) porphyrin (Zn2,3TDHPP) and Zn tetrakis(3,4-dihydroxyphenyl) porphyrin (Zn3,4TDHPP) with adjacent hydroxyl groups attaches to a TiO₂ surface much more strongly than carboxylate. The catechol anchoring group showed high stability of the dye on the TiO₂ surface. The cells prepared from these porphyrins showed no significant desorption of dye from the TiO₂ surface after several days. The DSSCs based on Zn2,3TDHPP showed the best photovoltaic performance under AM 1.5 irradiation comparable to the conventional Zn tetrakis(p-carboxyphenyl) porphyrin (ZnTCPP), despite lower dye loading on the TiO₂ surface. However, non-cooperative OH bonding to TiO₂ for Zn2,4TDHPP and Zn2,5TDHPP shows weak attachment to the TiO₂ surface and lower efficiencies. DFT calculations showed that the Zn2,3TDHPP structure is more non-planar than the others, which may suppress dye aggregation. The adopted adsorption modeling is fitted to the experimental data to study the kinetics of dye loading. The study can herald development of a new class of porphyrin sensitizer for DSSC applications.

Link: http://pubs.rsc.org/-/content/articlelanding/2016/ra/c5ra23584g/unauth#!divAbstract

امتیاز کاربران

Pooya Tahay, Meysam Babapour, Ali Alavi, Zahra Parsa, Nasser Safari^*

In order to provide a comprehensive investigation of nanoparticles size in relation with different dye types in DSSCs, three sizes of nanoparticles and two different dye types including a porphyrin dye (T2) and a ruthenium dye (N3) were synthesized. Steady state current–voltage (J–V) characteristics were investigated for fabricated DSSCs and the result demonstrated that optimum nanoparticles size changed with dye types. The obtained J–V data were interpreted by cyclic voltammetry, UV-visible absorption spectroscopy, BET measurement, DFT calculation, IPCE measurement and impedance spectroscopy. The results for the N3 dye show that the surface area of the nanoparticles is a key factor for the N3 cells which are restricted by pore diameter and surface state traps. In contrast, density of localized states of film under LUMO state of the porphyrin dyes is the dominating factor for performance of the solar cells, which are restricted by surface area of the nanoparticles. These obtained results represent a significant advance in the development of the porphyrin, ruthenium and even solid electrolyte DSSCs.

Link: http://pubs.rsc.org/-/content/articlelanding/2017/cp/c7cp01159h/unauth#!divAbstract