Structural and electronic study of iron-based dye sensitizers for solar cells using DFT/TDDFT

Abstract

Ruthenium-based molecules have proven their efficiency as photosensitizers in dye-sensitized solar cells. However, due to the high cost and scarcity of this noble metal, in this work we investigated the effects of replacing the ruthenium in photosensitizers with iron because it is less expensive and more abundant. DFT and TD-DFT methods were used to explore the resulting systems. The B3LYP functional was employed to compute the ground-state geometries and the frontier molecular orbitals for four complexes of general formula M(Rbpy)SNC (M = Ru or Fe; R = COOH or COOEt). We also used TD-M06 to investigate the electronic properties and to simulate the absorption spectra of these Ru-based and Fe-based complexes. Finally, CPCM was applied to explore the effect of DMF solvent. The HOMOs of these Ru-based and Fe-based molecules were found to have metal d orbital and π(SCN) orbital character, while their LUMOs had π*(R-bpy) orbital character. In addition, values of the light-harvesting efficiency (LHE), open circuit voltage (V ), and driving force (∆G) were calculated for the Ru-based and Fe-based molecules. According to our results, the maximum absorbance, the LHE, V , and ∆G values for complexes 2 and 4 (Fe-based dyes) are very close to those of complexes 1 and 3 (Ru-based dyes). Thus, our studies indicate that the Ru in photosensitizers can be replaced with the much less expensive metal Fe, as the resulting Fe-based dyes appear to be promising candidates for use in solar cells.

Promising sensitizers for dye sensitized solar cells: A comparison of Ru(II) with other earth's scarce and abundant metal polypyridine complexes

“…But due to the scarcity of these particular metals in earth's crust, the development of organic dyes or dyes with abundant metal ions for the DSSC studies are important. Iron (fourth abundant element in earth's crust) has very recently been used for DSSC with TiO 2 . Current studies also showed some applications of nickel, chromium, copper, and zinc metal ions (some other earth‐abundant metal ions) for DSSCs .…”

“…Iron (fourth abundant element in earth's crust) has very recently been used for DSSC with TiO 2 . [55][56][57] Current studies also showed some applications of nickel, chromium, copper, and zinc metal ions (some other earth-abundant metal ions) for DSSCs. [58][59][60][61][62][63][64][65] Nickel(II) polypyridyl complexes have also recently been used as a catalyst for hydrogen production from water.…”

Rational Design of Broadly Absorbing Boron Dipyrromethene-Carbazole Dyads for Dye-Sensitized Solar Cells: A DFT Study

“…The PCE provides a basis for the design of high-conversion-efficiency DSSCs and can be determined by theoretical methods using eq where FF refers to the fill factor, which was set at 0.68, and P inj denotes the power of the incident light ( P in = 100 mW cm –2 at AM 1.5). It is observed (Table ) that the PCE values of D1T, D1F, and D1P are 11.25, 12.13, and 13.50%, respectively.…”

Kajian Teoritik Efek Pelarut pada Coumarin untuk Aplikasi Dye Sel Surya

“…Molekular dye berbasis Ruthenium, Ru, merupakan salah satu dye yang paling efektif di DSSC sampai saat ini. Namun dikarenakan harga yang cukup mahal dan kelangkaan dari logam ini, banyak penelitian mengembangkan pengganti dari molekular dye berbasis Ruthenium dengan fokus di pigmen alami yang berasal dari alam sebagai alternatif penggantinya [12]. Beberapa pigmen organik alami yang ada pada tumbuhan dapat digunakan sebagai dye sensitizer di piranti DSSC adalah coumarin, merocyanine, cyanine, indoline, hemicyanine, triphenylamin, dialkylaniline, phenothiazine, tetrahydroquinoline, dan carbazole yang memiliki kemampuan mengkonversi energi matahari menjadi listrik dengan efisiensi sebesar 5% − 9% pada panel surya DSSC [13][14][15].…”