Studies on the reverse solvatochromism of dyes in pure solvents are of interest to gain a better understanding of the nature of this phenomenon and its application in organic solar cells. In this paper, azo-dye compounds (E)-6-((7-Aminonaphthalen-1-yl) Diazenyl)-2-decyl-1h-Benzo[de]Isoquinoline-1,3(2 h)-dione (ADBID) made from amino naphthalene and N-alkylated-isoquinoline groups linked with a diazenyl conjugated bridge, was synthesized and characterized using UV–vis, FT-IR, and H1-NMR. Furthermore, the compound was modelled and investigated theoretically using the density functional theory (DFT) at the B3LYP/6-31 + G(d) level theory at the ground state for the geometric optimization and further electronic calculation in different solvents systems for the solvatochromism effect. The frontier molecular orbitals, which include the quantum descriptors, highest occupied molecular orbitals (HOMO), lowest unoccupied molecular orbitals (LUMO), and energy gap (Eg) were determined at the ground state. The natural bond orbitals (NBO) and nonlinear optical (NLO) properties of newly designed ADBID molecules are examined and compared with the aid of DFT and TD-DFT in gas, water, EtOH, CHCl3 and DMSO in other to understand the solvent medium influence. The result indicates that, addition of solvent improves the overall photovoltaic properties, a red shift and as well as shows how the HOMO donates electron to the LUMO via the diazenyl group present in the dye, with an energy gap of 2.58eV making ADBID suitable for DSSCs fabrication regardless of the solvent polarity.