3D Structural Optimization of Zinc Phthalocyanine-Based Sensitizers for Enhancement of Open-Circuit Voltage of Dye-Sensitized Solar Cells

Takuro Ikeuchi,Yu Kitazawa,Shogo Mori,Mutsumi Kimura,Ryota Kudo

doi:10.3390/en13092288

Abstract

We designed and synthesized two zinc phthalocyanine sensitizers (PcS27 and PcS28), substituted with branched or cyclic alkoxy chains, to investigate the structural effect of peripheral alkyl chains on the performance of dye-sensitized TiO2 solar cells. The bulky cyclic alkyl chains of PcS28 decreased the adsorption density of PcS28 on the TiO2 electrode, while the terminal branches of alkoxy chains of PcS27 did not influence the adsorption density in comparison to the previously published PcS20 with linear alkoxy chains. Under one sun conditions, PcS27 cells exhibited higher open-circuit voltage but a slightly lower energy conversion efficiency, 6.0% less than PcS20. These results suggest that the small alternation of alkoxy chains resulted in decreasing electron pushing ability of peripheral phenoxy units, giving lower short-circuit current.

Highlights

Dye-sensitized solar cells (DSSCs) have drawn special attention as a promising alternative to conventional silicon-based solar cells [1,2]
The performances of DSSCs based on ZnPcs decorated with branched or cyclic alkoxy chains at the peripheral phenoxy units were examined
6.0% efficiency when used as a light-harvesting sensitizer on a TiO2 electrode under one sun conditions

Summary

Introduction

Dye-sensitized solar cells (DSSCs) have drawn special attention as a promising alternative to conventional silicon-based solar cells [1,2]. Whereas several chromophores with absorption bands in red and near-IR light regions have been applied as light-harvesting dyes for DSSCs, these chromophores have not shown high PCE values. This is partially because of the difficulty of matching. The approach attachment alkyl chains around chromophores chromophores has been reported as an effective to of enhance. TiO surfaces oc sensitizers form aand dense layer thebarrier interface of to dye-adsorbed and electrolytes, and electrolytes, the barrier formation of at this leads an increase in electron lifetime. Structural effect of alkyl chains around the Pc core on the photovoltaic properties

Methods

Differencial pulse electrospray ionization obtained on a Bruker

Results and Discussion

Absorption spectra

Photovoltaic performance of density

Conclusions