Electrochemically stable, cost-effective and facile produced selenium@activated carbon composite counter electrodes for dye-sensitized solar cells

Abstract

Dye-sensitized solar cells (DSSCs), as third generation photovoltaic technology, have been extensively investigated due to their numerous advantages, such as inexpensive and simple/fast preparation methods. As known, DSSCs are composed of different components. Counter electrode, which is one of the components, is an indispensable part of high-performance DSSCs. Designing new counter electrodes (CEs) with low cost and desired physical and electrochemical properties are important to achieve higher performance/stable DSSCs. In this sense, in this current report, new selenium@activated carbon (Se@AC) composites as alternative to expensive platinum (Pt) were produced by cost-effective and facile applied ball milling method, and used as CE in the DSSC architecture. Here, firstly, porous activated carbon (AC) was prepared from fruit peel wastes via chemical activation technique. Then the Se was incorporated into the structure of porous AC with different ratios to improve different physical and electrochemical properties of pristine AC. After Se incorporation strategy, the electro-catalytic activity and charge transfer parameters (RCT value decreased from 27.41 to 12.09 Ω cm2) of Se@AC composite CEs were significantly enhanced. The fabricated DSSC with a CE using Se@AC:3@5 showed a power conversion efficiency (PCE) value of 5.67% with current density (Jsc) of 13.26 mA/cm2, open-circuit voltage (Voc) of 648 mV and fill factor (FF) of 66%, which can acceptable close to the performance of the fabricated DSSC with the Pt-based CE (6.86%). The improvement electro-catalytic activity and charge transfer properties obtained with the low cost and facile production process could render the Se@AC composite CE standing out as an effective alternative to the precious/expensive Pt reference CE.