Regensburg 2019 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 12: HL Poster I

HL 12.21: Poster

Montag, 1. April 2019, 17:30–20:00, Poster E

Optical characterization of implanted transition metal dichalcogenides monolayers — •Minh Bui¹, Jhih-Sian Tu¹, Manuel Auge², Sven Borghardt¹, Eoghan O’Connell³, Ursel Bangert³, Hans Hofsäss², and Beata Kardynał¹ — ¹Peter Grünberg Institut 9, Forschungszentrum Jülich, Jülich, Germany — ²II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany — ³Department of Physics, School of Sciences and Bernal Institute, University of Limerick, Limerick, Ireland

Two dimensional semiconductors, such as monolayers (MLs) of transition metal dichalcogenides, possess some unique properties due to their band structure and geometry. In analogy to classic bulk semiconductors, it is desirable to introduce stable dopant atoms into their lattice in a controlled way for exploiting these properties. In this contribution, we investigate low energy ion implantation as a method to introduce foreign atoms into MoS₂ and MoSe₂ MLs. Raman, reflectance and photoluminescence spectroscopies, supported by transmission electron microscopy, are used to characterize the resulting semiconductors. Implantation of Se ions with energies below 50 eV into exfoliated MoS₂ MLs is studied as a prototypical system. Substitution of S with Se atoms should convert MoS₂ into MoSe_2xS_2(1−x) without generating free charge carriers. Implantation levels of up to few percent, much larger than needed for doping, are shown. We find that implanted ion energy is a compromise between implantation success rate and defect formation rate, and we identify the most likely defects. Similarly, results of MoSe₂ implanted with P as an n-type dopant are discussed.