MoS2/ZIF-8 derived nitrogen doped carbon (NC)-PEDOT: PSS as optically transparent counter electrode for dye-sensitized solar cells

Abstract

A few-layered MoS2 successfully grown on the nitrogen-doped carbon (NC) derived from zeolitic imidazolate framework (ZIF-8) via the hydrothermal method. A small portions of the obtained MoS2/NC composite blended with Poly (3, 4-ethylenedioxythiophene poly styrene sulfonic acid)PEDOT: PSS(as a conductive binder and utlized as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The spin-coated MoS2/NC-PEDOT: PSS composite on Fluorine-doped Tin Oxide (FTO) glass not only possesses promissing catalytic ability toward the I3-/I-and [Co(bpy)3]2+/3+ redox mediators but also displayed considerable optical transparency in the visible range thus used to fabricate bi-facial DSSCs. The assembled bi-facial devices with MoS2/NC-PEDOT: PSS composite CEs showed an excellent power conversion efficiency (PCE) under both the front and the rear irradiations. The PCE of the device with 5% MoS2/NC-PEDOT: PSS composite CE and I3-/I- redox couple are 7.67 and 4.54%, under the front and rear irradiation respectively. Also, the values of the device with the same composite CE and [Co(bpy)3]2+/3+ redox mediator are 7.87 and 5.34% under the front and rear irradiation, respectively. The optimum performance of the devices with the prepared CEs and both redox systems are comparable with Pt-based devices. Thus, the MoS2/NC-PEDOT: PSS composite CEs are recommend being a promising Pt-free CEs for DSSCs.