Impact of π spacers on the optical, electrochemical and photovoltaic performance of D-(π-A)2 based sensitizers

Abstract

A series of D-(π-A)2 organic dyes with different p spacers have been designed and synthesized. The modification of the bianchoring dyes regarding p spacers assists in tuning the photochemical and electrochemical properties of the dyes, which determine the open circuit voltage (VOC), short circuit current density (JSC) and hence overall power conversion efficiency. It is found that varying the spacers has more influence on determining the short circuit current density of the solar cell devices made with these sensitizers. When thiophene is used as p spacer, higher short circuit current density of 9.42 mA/cm2 is observed. The better IPCE of the dye with thiophene as spacer further supports its advantage over other spacers. The observed tunable light harvesting property, electrochemical and photovoltaic behaviour by varying the p spacers in D-(π-A)2 type sensitizers will provide fruitful information for future designing of sensitizers with multianchoring modes.