The fluorescence properties of bisphenol A polycarbonate (PC) solids were studied in detail as a function of casting and annealing temperatures (40-180 degrees C), resulting in the establishment of a method to measure the pure fluorescence spectrum of PC solids. The spectrum was subject to contamination by a photoproduct of PC, which was assumed to have a similar structure to 2,2’-dihydroxydiphenyl. The existence of an excimer, formed between intermolecular phenyl groups in the PC main chain, was ascertained, showing that some main chains are located with a distance of 0.35 nm between one another in the amorphous area of PC solids.