Attosecond-fast internal photoemission

Christian Heide , Martin Hauck , Takuya Higuchi , Jürgen Ristein (1) , Lothar Ley (1) , Heiko Weber , Peter Hommelhoff (2)

1 Lehrstuhl für Technische Physik
2 Fakultät für Physik [Garching]

The photoelectric effect has a sister process relevant in optoelectronics called internal photoemission1,2,3. Here an electron is photoemitted from a metal into a semiconductor4,5. While the photoelectric effect takes place within less than 100 attoseconds (1 as = 10−18 seconds)6,7, the attosecond timescale has so far not been measured for internal photoemission. Based on the new method CHArge transfer time MEasurement via Laser pulse duration-dependent saturation fluEnce determinatiON—CHAMELEON—we show that the atomically thin semimetal graphene coupled to bulk silicon carbide, forming a Schottky junction, allows charge transfer times as fast as (300 ± 200) as. These results are supported by a simple quantum mechanical model simulation. With the obtained cut-off bandwidth of 3.3 PHz (1 PHz = 1015 Hz) for the charge transfer rate, this semimetal/semiconductor interface represents a functional solid-state interface offering the speed and design space required for future light-wave signal processing.

Domaines: Optique / photonique

Christian Heide, Martin Hauck, Takuya Higuchi, Jürgen Ristein, Lothar Ley, et al.. Attosecond-fast internal photoemission. Nature Photonics, 2020, ⟨10.1038/s41566-019-0580-6⟩. ⟨cea-02462468⟩