Publication
Hybrid dye-sensitized solar cells with graphene—A convenient method to seal liquid state devices
Publisher:
AIP Publishing
Date:
07-2018
DOI:
10.1063/1.5037150
Abstract: Hybrid dye-sensitized solar cells were fabricated with an iodide/triiodide based liquid electrolyte and graphene as the hole transporting material to overcome the leakage problem associated with liquid state devices. Here, a thin layer of the iodide/triiodide based liquid electrolyte was drop cast onto the working electrode which consists of a dye coated mesoporous TiO2 layer. Then, this thin layer of the liquid electrolyte was sealed with a layer of graphene by the doctor blade method. A platinized transparent conducting oxide glass was used as the counter electrode to complete the device. An overall energy conversion efficiency of 6.13 ± 0.10% with a VOC of 645 ± 20 mV and a JSC of 14.4 ± 1.2 mA cm−2 was observed under AM 1.5 irradiation (1000 W m−2). These devices exhibit a maximum incident photocurrent conversion efficiency of 51.6% which was observed at a wavelength of 525 nm. Furthermore, electrochemical impedance spectroscopy measurements revealed that the charge transfer resistance at the counter electrode/electrolyte interface was significantly reduced compared to the standard iodide/triiodide redox mediator after applying graphene as the hole transporting material which may promote efficient charge transfer within the device.