Identification of multiphoton induced photocurrents in metal-insulator-metal junctions

• Published in: Applied physics. B, Lasers and optics Vol. 78; no. 3-4; pp. 443 - 446
• Main Authors: DIESING, D, MERSCHDORF, M, THON, A, PFEIFFER, W
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.02.2004
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrodes; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Excitation; Illumination; Lasers; Photoconduction and photovoltaic effects; Photoconduction and photovoltaic effects; photodielectric effects; Photocurrent; Photoelectric effect; Physics; Transport; Tunneling; Time resolved spectroscopy; Ultrashort pulse; Carrier lifetime; Multiphoton excitation; Photoinduced effect; MIM junctions; Multi-photon processes; Photocurrents; Laser irradiation; Experimental study; Pulsed lasers; Charge carrier injection
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-003-1391-4

Illumination of metal--insulator--metal junctions with ultrashort laser pulses and multiphoton electron excitation in the top electrode leads to the injection of electrons into the backside electrode. Time resolved photocurrent spectroscopy shows that the carrier injection is not instantaneous but occurs with an effective lifetime of about 30 fs. The observation of an effective lifetime reveals that photon-assisted tunneling is negligible. It is shown that three-photon induced internal photoemission and two-photon induced tunneling of excited electrons are the dominating transport mechanisms.