Formation of nanosized carbonaceous clusters has been investigated in 100 keV ${\mathrm{N}}^{+}$ irradiated poly(2,6-dimethyl-1,4-phenylene oxide) [PPO] thin films, using Fourier transform (FT)-Raman, transmission electron microscopy and UV-Vis spectroscopy in the fluence range of $1\ifmmode\times\else\texttimes\fi{}{10}^{15}\ensuremath{-}5\ifmmode\times\else\texttimes\fi{}{10}^{16} {\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{s}/\mathrm{c}\mathrm{m}}^{2}.$ Above a critical fluence of $\ensuremath{\sim}1\ifmmode\times\else\texttimes\fi{}{10}^{16} {\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{s}/\mathrm{c}\mathrm{m}}^{2},$ the energy density transferred to the implanted layer resulted in a molecular construction/self-organization process with the evolution of graphitelike clusters of varying size $\ensuremath{\sim}2\ensuremath{-}50 \mathrm{}\mathrm{nm}.$ Electron diffraction analysis of these clusters shows a close resemblance to the formation of single crystalline graphite phase with a zone axis $〈070〉.$ The deduced band gaps from the optical spectra using Tauc's approximation provided information on the electronic structure of the fused hexagonally clustered aromatic rings with varying sizes; the number of the rings varying from $\ensuremath{\sim}20\ensuremath{-}170.$ Evidence for the signature of fractal patterns, with dimension $1.37\ifmmode\pm\else\textpm\fi{}0.02,$ during aggregation of small particlelike clusters in the polymer implanted layer is presented; analysis of the data suggests the growth process to follow a diffusion-limited-aggregation model.