The present invention relates to an unsymmetrical squaraine dye of formula (I) and process for the preparation thereof. The process includes dissolving a 3-cycloalkene-1,2-dione compound in acetone and aqueous HCl to afford a semisquaraine compound. The process includes refluxing the semisquaraine compound and phenyl carboxylic acid dissolved in solvent to afford the unsymmetrical squaraine dye. Further, the present invention relates to an electronic device with an enhanced device efficiency containing a dye of formula (I) co-sensitized with a squaraine dye.