A systematic study of phenoxazine-based organic sensitizers for solar cells. (February 2017)

• Record Type: Journal Article
• Authors: Li, Ping; Cui, Yahui; Song, Chongping; Zhang, Houyu
• Is Part Of: Dyes and pigments. Volume 137(2017)
• Page Start: 12
• Page End: 23
• Publication Date: 2017-02
• Subjects: Dye sensitized solar cell -- Organic dye -- Phenoxazine(POZ) -- DFT calculations; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2016.09.060
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: We perform a systematic theoretical and computational investigation of phenoxazine (POZ)-based organic dyes to rationalize the marked difference in the energy conversion efficiency. The geometries, electronic structures and absorption spectra of the dyes and their adsorbed dye-TiO2 systems are carried out by means of density functional theory (DFT) and time-dependent DFT methods. The relevant physical parameters that dominate the performance of the cell, such as the light harvesting efficiency (ΦLHE ), exciton binding energy (Eb ), the driving force for electron injection (Δ G inj ), the conduction band shift (ΔECB ), and transferred charges ( n c ) are assessed in detail to determine their contributions to either the short-circuit photocurrent density (Jsc ) or the open-circuit photovoltage (Voc ), and establish the structure-property relationships. The calculated results elucidate that the extension of π -spacer, the introduction of di-anchoring group and auxiliary chromophores make significant influence on the PCE of the cells. The designed dyes with the introduction of elongated π -spacer, N-phenlycarbazole substitution at the 7-position of POZ and thiophene-linked di-anchoring group could be potential POZ-based candidates used in DSSCs. We hope that our calculations give a more in-depth physical insight on structure-property relationship for POZ-based dyes and provide a hint to design and screen novel high performance POZ-like dyes. Graphical abstract: A systematic study of POZ derivatives are carried out theoretically to establish the structure-property relationship for screening high performance POZ-based sensitizers used in dye sensitized solar cells. Highlights: Phenoxazine-based dyes were investigated to establish structure-property relationship. Appropriate extension of π bridge of dye is favorable to improve the J sc . Di-anchoring sensitizer might be helpful for dyes adsorbed on the TiO2 surface. Introduction of different chromophores could enhance the CT character of the dyes.