Effect of an aqueous copper gel electrolyte with cobalt metal organic framework based additive on performance of aqueous-dye-sensitized solar cells. (1st April 2022)

• Record Type: Journal Article
• Authors: Selvaraj, Balamurugan; Shanmugam, Ganesan; Kamaraj, Santhosh; Thirugnanasambandam, Eswaramoorthi; Gunasekeran, Ahalya; Sambandam, Anandan
• Is Part Of: Solar energy. Volume 236(2022)
• Page Start: 586
• Page End: 598
• Publication Date: 2022-04-01
• Subjects: Heteroleptic copper redox mediator -- Mono-ligands approach -- MOF-additive -- Aqueous gel polymer electrolytes and Dye-sensitized solar cells; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2022.03.034
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: An aqueous copper gel electrolyte with MOF reached higher PCE of 3.42% in aqueous-DSSCs. Highlights: Novel heterolepctic copper mediators are introduced for the first time in DSSCs. As-synthesized Co-MOF plays as best additive materials to controls recombination. An aqueous copper gelrite polymer electrolyte attains higher efficiency of 3.42%. Milestone efficiency was achieved in aqueous DSSCs with N719 dye. Abstract: A simple mono-dentate ligand substitution approach was studied to design three new potential tunable heteroleptic copper redox mediators with general formula [Cu (bnbip) (X)] 1+/2+ where, bnbip is a tridentate ligand, (2, 6-bis(1-(naphthalen-2-ylmethyl)-1H-benzo[d]imidazol-2-yl)pyridine), X = 4- tert -butylpyridine (tbp), 4-chloropyridine (cp) and 5-methoxy-1-(pyridin-4-yl)-1H-indole (mpi). Herein, copper mediator bearing bulky high donor ligand (mpi) reached best redox potential of 0.72 V vs NHE, which directly improves Voc and Jsc of the dye-sensitized solar cells (DSSC) devices because of its lower reorganization energy and driving force. A series of six aqueous gel electrolytes were prepared as G-1, G-2, G-3 (without additive) and G-4, G-5, G-6 (with Co-MOF additive) to analyze the role of three different heteroleptic copper redox couples and Co-MOF in aqueous gelrite polymer electrolytes. Impressively, electrolytes G-4, G-5 and G-6 affords higher PCE of 2.03, 2.12 and 3.42% under 1sun condition than electrolytes without additives, which proves the role of Co-MOF as an additive to reduce recombination process. This control in recombination occurred due to high interaction of repeating carboxylate donor groups of additive with TiO2 surface and Cu 2+ ion of redox pair. The electrolyte material G-6 consists of Cu +1/+2 [(bnbip)(mpi)] redox mediator, Co-MOF additive and aqueous geltrite polymer host obtained higher Jsc and PCE which were sustained via many aspects, such as high conductivity, larger charge, higher chemical capacitance, longer electron lifetime, a shift in the quasi-Fermi level of TiO2, lower recombination of electrons and fast dye regeneration.