Abstract Excellent Langmuir–Blodgett (LB) films of 9,10-diphenylanthracene (DPA) and α,α-linked sexithiophene (6T) with arachidic acid (AA) can be formed on water subphase and can be transferred on to quartz substrates. Electronic absorption and emission spectra of these films have been studied and compared with those in solution. Results suggest formation of aggregates of DPA and 6T in LB films. 6T has been used as a quencher for the DPA donor fluorescence. It is shown that the efficiency of energy transfer from the donor to the acceptor decreases with the quadratic power of the distance separating them. Such quadratic dependence confirms that the donor excitation is delocalized.