Enhanced efficiency of dye co-sensitized solar cells based on pulsed-laser-synthesized cadmium-selenide quantum dots. (October 2020)

• Record Type: Journal Article
• Authors: AlGhamdi, Jwaher M.; AlOmar, Shorooq; Gondal, Mohammed A.; Moqbel, Redhwan; Dastageer, Mohamed A.
• Is Part Of: Solar energy. Volume 209(2020)
• Page Start: 108
• Page End: 117
• Publication Date: 2020-10
• Subjects: Pulsed laser ablation in liquids -- CdSe -- Quantum dots -- Co-sensitization -- Dye sensitized solar cells -- Photovoltaic; DSSC dye-sensitized solar cell -- QD quantum dot -- PLAL pulsed laser ablation in liquid -- PV photovoltaic -- UV ultraviolet -- QDSSC quantum dot-sensitized solar cell -- CB conduction band -- XPS X-ray photoelectron spectroscopy -- TEM transmission electron microscopy -- MLCT metal-to-ligand charge transfer -- PL photoluminescence -- FF fill factor -- HOMO highest occupied molecular orbital; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2020.08.091
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: Highlights: DSSCs, in which TiO2 is co-sensitized by N719 dye and CdS-QD was fabricated. Photovoltaic conversion efficiency of 7.1 % was achieved in the new configuration. This accounts for 33% increase of efficiency compared to usual TiO2 based DSSC. Optimum band structures and charge transfers are attributed for this performance. Band positions and charge transfer mechanisms in co-sensitized DSSC is explained. Abstract: In this study, a new configuration of dye sensitized solar cells (DSSCs), in which a TiO2 photoanode is co-sensitized by N719 organic dye and CdSe quantum dots (CdSe-QDs), was fabricated. The photovoltaic performance of the cell, which was co-sensitized with an optimum concentration of CdSe-QDs, was found to be superior to that of the cell with a photoanode sensitized using N719 dye. The superior performance can be attributed to the energy-compatible band structures of the N719 dye molecule and the CdSe-QDs, selective transfer of a significant number of photogenerated electrons from the energy state of the dye molecule to the conduction band (CB) of CdSe-QDs, and improved absorbance of the CdSe-QDs in the visible-light spectrum. This initial inflow of electrons to the dye was found to enrich the subsequent dye-mediated electron transfer to TiO2, thus contributing to the enhanced photocurrent in the DSSC. The novel material implemented in this study was based on CdSe-QDs, which were used as a co-sensitizer in the photoanode of the DSSC synthesized by pulsed laser ablation in liquid (PLAL). Morphological, structural, elemental, optical and electrochemical characterizations of the photoanodic materials were conducted; and the photovoltaic characteristics of the fabricated cell were determined. The photovoltaic conversion efficiency of the cell co-sensitized by CdSe-QDs at a certain concentration (1 mg/15 ml of ethanol) and N719 dye was found to be 7.09%, which corresponds to a 37% enhancement of the photovoltaic efficiency when compared with the cell sensitized only by the N719 dye.