<p>Herein, we report the synthesis and characterization of a new phenyl-flanked <i>N</i>-substituted diketopyrrolopyrrole (DPP)-based molecular semiconductor, namely 2,5-bis(2-(4-chlorophenyl)-2-oxoethyl)-3,6-diphenyl-pyrrolo[3,4-c]pyrrole-1,4-dione (DPP-PCP)-based molecular semiconductor. The structure of the synthesized DPP-PCP was confirmed on the basis of nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy, ensuring high purity. Density functional theory (DFT) calculations estimated the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy levels at −5.80&#xa0;eV and −3.18&#xa0;eV, respectively. Experimentally, ultraviolet (UV)–visible spectroscopy and cyclic voltammetry determined the HOMO, LUMO, and optical bandgap as −5.13&#xa0;eV, −2.94&#xa0;eV, and 2.19&#xa0;eV, showing good agreement with theoretically calculated values. The low-lying HOMO energy level indicates compatibility with high work function anodes for stable electronic devices applications. Thermogravimetric analysis (TGA) demonstrated thermal stability up to 396°C. Self-powered photodetectors offer energy-efficient operation without external bias, making them ideal for next-generation, low-power optoelectronic applications. A self-powered hybrid organic–inorganic photodetector with an Ag–DPP-PCP–Si–Ag structure was fabricated, achieving a responsivity of 8.73 × 10⁻² mAW⁻¹ and a detectivity of 7.9 × 10⁹ Jones under UV-A (365&#xa0;nm) illumination and are comparable and better than that reported in literature. The material’s superior thermal, optical, and electrochemical properties highlight its potential for high-performance organic electronic applications.</p> Graphical Abstract <p>Molecular structure and calculated frontier molecular orbitals of DPP-PCP, energy level diagram, and time-dependent photo-response of self-powered hybrid organic–inorganic photodetector at variable radiation intensities</p> <p></p>