Experimental and theoretical studies of the electrochemical properties of mono azo dyes derived from 2-nitroso-1- naphthol, 1-nitroso-2-naphthol, and C.I disperse yellow 56 commercial dye in dye-sensitized solar cell

Quantum chemical computational tools were used to investigate the charge transfer electron excitation of two mono azo dyes derived from 2-nitroso-1- naphthol, 1-nitroso-2-naphthol, and C.I Disperse Yellow 56 commercial dye. The studied compounds were experimentally synthesized and characterized using UV-Vis and FT-IR spectrophotometry. Theoretical calculations were conducted with the synthesized dyes using density functional theory (DFT) and time-dependent DFT with 6-311+G(d,p) basis set in acetone, chloroform, DMSO, ethanol, gas, and water respectively. The solvent model (CPCM) is used in the calculations. The photovoltaic properties of the studied compounds were analyzed in terms of open-circuit voltage (Voc), electron injection, light-harvesting efficiency (LHE), HOMO-LUMO, and energy gap. The highest oscillator strength transition is observed at the HOMO–LUMO region of all the studied dyes molecules at 0.0534, 0.0012, 0.0048, 0.0543, 0.0542, 0.0024, 0.0074, 0.0534, 0.4903, 0.0531 for dye DA, DB, and DC in the various solvents respectively. Dye DC and DB gave the highest energy gap in acetone, DMSO, ethanol, gas, water, and chloroform media respectively. Interestingly, the LHE of the dyes was high in all the solvents used with the highest result obtained in acetone at 0.7308 for dye DC. The ∆Greg varies between -10.5 eV to11.8 eV in all the studied solvents which indicates a high electron injection capacity within the studied dyed molecules. The open-circuit voltage Voc, the ΔGinject and ΔGreg values for the selected molecule play a vital role in the comparison of both the selected dyes and thus they can be regarded as promising molecules for application in dye-sensitized solar cells.