SKM 2021 – wissenschaftliches Programm

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SYAW: Awards Symposium

SYAW 1: Prize Talks

SYAW 1.2: Preisträgervortrag

Mittwoch, 29. September 2021, 14:00–14:30, Audimax 1

PbTe/CdTe nanocomposite as an attractive candidate for room-temperature infrared detectors — •Grzegorz Karczewski — Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warszawa, Poland — Laureate of the Smoluchowski-Warburg-Prize 2021

The presentation will be devoted to describe the morphological, optical and transport properties of a PbTe/CdTe nanocomposite. Such a nanocomposite is fabricated by depositing alternating multiple PbTe and CdTe thin films by molecular beam epitaxy (MBE). PbTe and CdTe are immiscible. The immiscibility is due to the different crystal structures in which the two materials crystallize (PbTe in the rock salt and CdTe in the zinc blende structure). The observed topological transitions leading to material separation in the PbTe/CdTe system can be treated as an analogue of the spinodal decomposition of an immiscible solution in the solid state and thus can be qualitatively described by the Cahn-Hillard model.

Resistors made of the PbTe/CdTe nanocomposite exhibit pronounced sensitivity to infrared radiation at room temperature. Possible mechanisms causing the relatively high performance of PbTe/CdTe detectors are the decrease in electron concentration in the conductive PbTe layers due to the capture of mobile electrons by the dangling bonds present at the PbTe/CdTe interfaces and the effective suppression of Auger recombination in nanostructures made of narrow and wide band gap semiconductors.