| 释义 |
exciton Physics.|ˈɛksɪtɒn, ɛkˈsaɪtɒn|
[f. excitation 5 + -on.]
In a crystalline semi-conductor or insulator, an excited electron and an associated hole which together form a concentration of energy with certain properties characteristic of a particle.
1936J. Frenkel in Phys. Zeitschr. der Sowjetunion IX. 159 Just as the positive hole can be pictured as a collectivized positron, the excited state can be pictured as a kind of particle which we shall call a (collectivized) exciton. 1938Nature 7 May 839/1 An exciton can move a certain distance through the crystal by transferring its energy from atom to atom, before the energy is all dissipated. 1967Condon & Odishaw Handbk. Physics (ed. 2) vi. vii. 155/2 An exciton in a crystal such as KCl is considered to result from the transfer of an electron from Cl- to K+, forming an excited and neutral KCl combination... Excitons can migrate through the crystal by exchange of condition with lattice ions. 1968New Scientist 14 Nov. 384/1 Excitons are quasiparticles which arise in semiconductor crystals.
Hence exciˈtonic a.
1958Physical Rev. Lett. I. 452/1 For these materials the dissociation energies of the ‘excitonic ion’ + + - and the ‘excitonic molecule’ + + - - are an appreciable fraction of the binding energy of the exciton itself. 1966New Scientist 27 Oct. 175/1 Known as the excitonic molecule, this stable entity is built up of two electrons and two ‘holes’. 1969Sci. Jrnl. Mar. 15/1 Fenton's arguments do not favour a resistanceless flow of electrons in dna, but rather that the molecule might be what he calls an excitonic insulator. |