Low-temperature photocarrier dynamics in single-layer MoS2 flakes

T. Korn; G. Plechinger; S. Heydrich; M. Hirmer; F.-X. Schrettenbrunner; D. Weiss; J. Eroms; C. Schüller

doi:10.1117/12.928067

15 October 2012 Low-temperature photocarrier dynamics in single-layer MoS₂ flakes

T. Korn, G. Plechinger, S. Heydrich, M. Hirmer, F.-X. Schrettenbrunner, D. Weiss, J. Eroms, C. Schüller

Proceedings Volume 8456, Nanophotonic Materials IX; 84560H (2012) https://doi.org/10.1117/12.928067
Event: SPIE NanoScience + Engineering, 2012, San Diego, California, United States

Abstract

The dichalcogenide MoS₂, which is an indirect-gap semiconductor in its bulk form, was recently shown to become an efficient emitter of photoluminescence as it is thinned to a single layer, indicating a transition to a direct-gap semiconductor due to confinement effects. With its layered structure of weakly coupled, covalently bonded two-dimensional sheets, it can be prepared, just as graphene, using mechanical exfoliation techniques. Here, we present temperature-dependent and time-resolved photoluminescence (PL) studies of single-layer MoS₂ flakes. Some of the flakes are covered with oxide layers prepared by atomic layer deposition (ALD). At low temperatures, we clearly see two PL peaks in the as-prepared flakes without oxide layers, which we may assign to bound and free exciton transitions. The lower-energy, bound exciton PL peak is absent in the oxide-covered flakes. In time-resolved PL measurements, we observe very fast photocarrier recombination on the few-ps timescale at low temperatures, with increasing photocarrier lifetimes at higher temperatures due to exciton-phonon scattering.

Citation Download Citation

T. Korn, G. Plechinger, S. Heydrich, M. Hirmer, F.-X. Schrettenbrunner, D. Weiss, J. Eroms, and C. Schüller "Low-temperature photocarrier dynamics in single-layer MoS₂ flakes", Proc. SPIE 8456, Nanophotonic Materials IX, 84560H (15 October 2012); https://doi.org/10.1117/12.928067

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available