Light emission induced by tunneling electrons from surface nanostructures observed by novel conductive and transparent probes.
We have developed an ultrahigh-vacuum low-temperature scanning tunneling microscope (STM) equipped with a near-field optical detection system using novel conductive and optically transparent probes. Tunneling-electron induced photons generated in a nanometer-scale area just under the STM probe can be collected directly into the core of the optical fiber probe within the optical near-field region. Firstly, optical fiber probes coated with indium-tin-oxide thin film are applied to quantitative analysis of p-type GaAs(110) surface, where a decrease of light emission in photon mapping clearly extracts the existence of Zn accepter atoms located at the sub-surface layers. Secondly, in order to enhance the efficiency for inelastic tunneling excitation of a tip-induced plasmon mode, a STM probe coated with an Ag/ITO dual-layer film has been developed and applied to an Ag(111) surface, where photon mapping with a step resolution has been achieved by near-field detection.
Fujita
Daisuke
D
Nanomaterials Laboratory, National Institute for Materials Science, 1-2-1 Sengen, Tsubuka, Ibaraki 305-0047, Japan. fujita.daisuke@nims.go.jp
Onishi
Keiko
K
Niori
Noriko
N
D000535:Aluminum / Q000737:chemistry; D001152:Arsenicals / Q000737:chemistry; D004583:Electrons; D005708:Gallium / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D049449:Luminescence; D016252:Microscopy, Scanning Tunneling / Q000295:instrumentation*; D049329:Nanostructures / Q000737:chemistry*; D017785:Photons; D015032:Zinc / Q000737:chemistry
D001152:Arsenicals; C043055:gallium arsenide; D006046:Gold; D005708:Gallium; D000535:Aluminum; D015032:Zinc