Charge-transfer dynamics in one-dimensional C60 chains

Abstract

Charge transfer in highly-ordered C60 chains grown on a Cu(5 5 3) vicinal surface is studied by means of resonant photoemission. Tuning the light polarization, autoionization of the highest occupied molecular orbital (HOMO) was expected to detect anisotropy in this one-dimensional system. For one monolayer C60 we found no signature of autoionization. This indicates that for an electron which is excited from the C 1s level of C60 to the lowest unoccupied molecular orbital (LUMO), hybridization leads to delocalization on the femtosecond time-scale and no influence of the light polarization is observed. Charge-transfer Dynamics in AbstractCharge transfer in highly-ordered C 60 chains grown on a Cu(553) vicinal surface is studied by means of resonant photoemission. Tuning the light polarization, autoionization of the highest occupied molecular orbital (HOMO) was expected to detect anisotropy in this one-dimensional system. For one monolayer C 60 we found no signature of autoionization. This indicates that for an electron which is excited from the C 1s level of C 60 to the lowest unoccupied molecular orbital (LUMO), hybridization leads to delocalization on the femtosecond time-scale and no influence of the light polarization is observed.

LUMO photoemission lineshape in quasi-one-dimensionalC60chains

“…For the C 60 chains it is possible that a metallic Fermi edge remains because the 1D character of the LUMO is reduced due to hybridization with the substrate which may assist interchain hopping. Indeed, recent experiments aiming to investigate the charge-transfer dynamics along and perpendicular to the chains, 33 indicated an important role of the metal substrate in delocalizing the LUMO electrons across the steps.…”

A Study on the Electron Transfer at the Alq3/Ba and Alq3/Au Interfaces by NEXAFS Spectroscopy

“…또한, q 3 Al(q=8-퀴놀리노라토 리간드; Al=알루미늄), q 2 AlOR (OR=아릴록시 및 알콕사이드 리간드) 4 . 음극/유기물 계면에서의 전자주입에 대 한 에너지장벽(Φ e )은 음극과 유기물의 페르미 준위 가 고정(pinning)될 때 유기물의 최저 비점유 분자 궤도(lowest unoccupied molecular orbital; LUMO) 준위와 페르미 준위 사이의 에너지 차이로 정의된 다. Φ e 는 수식 (1)과 같이 유기재료의 특정 원자 끝 머리 NEXAFS 스펙트럼의 전자 천이와 특정 원자 의 엑스선 전자방출 스펙트럼(x-ray photoemission spectrum)에서 E B 를 통해 측정될 수 있다 10) . 단, 이 러한 특정 원자의 전자천이 과정 중에 핵심 들뜸 효과에 의한 에너지 차이는 보정되어야 한다 8) .…”