PRESSURE EFFECTS ON SINGLE MOLECULES OF TERRYLENE IN P-TERPHENYL

The hydrostatic-pressure shift of the zero-phonon lines of single terr ylene molecules in a p-terphenyl host crystal was measured at 1.6 K. W e found four inhomogeneous absorption bands of the terrylene molecules in p-terphenyl with inhomogeneous widths between 15 and 33 GHz, corre sponding to four crystal sites, and we measured the pressure shift of single molecules in the sites X(2), X(3), and X(4). All the molecules investigated (35 in total) exhibited a linear and reversible red-shift with increasing pressure, with magnitudes between -0.92 and -1.48 MHz /hPa. The pressure shift parameter was found to be independent of the spectral position of the molecules.