Author/Authors :
Roth، نويسنده , , S. and Leuenberger، نويسنده , , D. and Osterwalder، نويسنده , , J. and Dahl، نويسنده , , J.E. and Carlson، نويسنده , , R.M.K. and Tkachenko، نويسنده , , B.A. and Fokin، نويسنده , , A.A. and Schreiner، نويسنده , , P.R. and Hengsberger، نويسنده , , M.، نويسنده ,
Abstract :
Diamondoids are nanometer-sized, hydrogen terminated diamond-like molecules consisting of fused adamantane units. The thiolated diamondoid [121]tetramantane-6-thiol shows negative electron affinity behavior, i.e. population of unoccupied states directly leads to spontaneous electron emission. We present time-resolved photoemission data from self-assembled monolayers of [121]tetramantane-6-thiol in order to shed light on the emission process: A photon energy threshold for electron emission of 5.6–5.8 eV was observed, and the electron affinity was estimated to be −0.21 to −0.57 eV for Ag and Au substrates, respectively. Electrons are emitted after excitation in the metal substrate through the molecular orbitals within a few femtoseconds.
