Hydroxyl solvents prompted interwoven morphological deposition of iron sulfide nanoparticles as an effective counter electrode for quantum dot sensitized Solar cell

A low-cost, stable and efficient FeS thin film counter electrode (CE) was fabricated for quantum dot sensitized solar cells (QDSSCs) by a facile chemical bath deposition method using different acidic hydroxyl solvents (ethanol, isopropanol, and tert-butanol) and triethanolamine. The choice of solvents greatly affected the surface morphology and thickness of FeS CEs. Apart from surface morphology, the increase in the atomic percentage of sulfur in tert-butanol and triethanolamine-mediated FeS also plays a crucial role in increasing the electrocatalytic activity of the CE. The QDSSC's power conversion efficiency was 2.15%, which is attributed to the high fill factor (FF) of 0.443. The obtained PCE is far better than the previously reported value of 1.76% for FeS in QDDSC's. Excellent stability of the photoelectric performance of the FeS CE is also demonstrated. The enhanced electrochemical performance of the interwoven FeS networks can be attributed to their unique morphology, which possesses a shorter diffusion length of the ions and easier transportation of the electrons. (C) 2016 Elsevier Ltd. All rights reserved.