Photoluminescence submicrometre spatial modulation of 6,13 pentacenequinone thin films

We demonstrate that uniform films of 6,13-pentacenequinone (PQ) deposited by vacuum thermal evaporation on prepatterned PMMA/Si(1 0 0) substrates yield under UV illumination a yellow photoluminescence (PL) response with strong spatial modulation at the micrometre (and submicrometre) scale. The PL patterns are obtained from engineered lithographed substrates (arrays of PMMA lines on bare Si(1 0 0) fabricated by x-ray interference lithography, using a tabletop 46.9 nm Ar laser). Strongly enhanced light emission is observed in correspondence to the PQ film lying on the PMMA lines with a PL efficiency 10 +/- 1 times higher than the one measured on the PQ/Si interface.