A comparative study on properties of two phenoxazine-based dyes for dye-sensitized solar cells

•Two phenoxazine-based dyes have been synthesized for a comparatively study.•The result shows that POZ-2 exhibited higher η of 6.5% than POZ-1 (η = 2.4%).•Conjugated direction is the crucial influential factor of η.

Two phenoxazine (POZ)-based organic D–π–A sensitizers (POZ-1 and POZ-2) were synthesized. Then these two dyes were applied in dye-sensitized solar cells (DSSCs) to investigate the influence of different conjugated direction, extra phenyl ring and alkyl chain on the light-harvesting, energy level and photovoltaic properties through a joint spectral, electrochemical and photovoltaic study. The result shows that dye POZ-2 exhibits higher power conversion efficiency (η = 6.5%) than dye POZ-1 (η = 2.4%) under standard illumination (Global Air Mass 1.5). Besides, the geometries of the dyes were optimized to gain insight into the molecular structure and electron distribution. The charge extraction and transient photovoltage decay measurements were further performed to understand the alterative order of efficiency.

Graphical abstractTwo phenoxazine-based organic (POZ-1, POZ-2) dyes were synthesized for a comparatively study.Figure optionsDownload full-size imageDownload as PowerPoint slide