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Aiming to Better Understand the Surface of Silicon

Physicist at Freie Universität Berlin Awarded Carl Ramsauer Prize

№ 351/2011 from Nov 16, 2011

Christian Eickhoff from the Department of Physics, Freie Universität Berlin, was awarded the 2011 Carl Ramsauer Prize for his doctoral dissertation. The prize was awarded by the German Physical Society in Berlin for his doctoral dissertation entitled "Zeitaufgelöste Zweiphotonen-Photoemission an der Si(001)-Oberfläche: Dynamik heißer Elektronen und zweidimensionaler Fano-Effekt." With his dissertation, Eickhoff aimed to gain a better understanding of the silicon (001) surface, one of the major surfaces in the semiconductor industry and a basic component of most solar cells. The award includes 1,500 euros.

For experiments to study the silicon (001) surface, Eickhoff designed a special laser system and an ultra-high vacuum apparatus, which enabled him to observe the behavior of electrons on the silicon surface with a time resolution of a few quadrillionths of a second. He noted that under certain conditions, the optical excitation of charge carriers at the surface leads to complex interference phenomena. He was also able to show why the increased temperature of hot electrons in the conduction band of silicon persists for an unusually long period of time, a process that was not previously clear for silicon. The extraction of these electrons is currently being discussed in the literature with regard to increasing the efficiency of solar cells.

Christian Eickhoff first studied physics in Münster. In 2005 he started working on his dissertation at the Max Born Institute in Berlin-Adlershof and at Freie Universität Berlin. He currently conducts research in the laboratory of Professor Martin Weinelt at Freie Universität's Department of Physics.

The Carl Ramsauer Prize is awarded annually by the German Physical Society of Berlin in honor of the eminent physicist and first director of the AEG Research Institute, the experimental physicist Carl Ramsauer (1879–1955). Each year it is awarded for four outstanding doctoral theses in physics and related fields of science.

Further Information

Dr. Christian Eickhoff, Email:, Tel.: +49 (030) 838-56047



Christian Eickhoff, Martin Teichmann, and Martin Weinelt: “Two-State Double-Continuum Fano Resonance at the Si(100) Surface”. Phys. Rev. Lett. 107, 176804 (2011) -