| AVS 61st International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+AS+EM+MI+MN+NS+TF-WeA |
| Session: | Properties of 2D Materials |
| Presenter: | Michael Watson, Towson University & NIST |
| Authors: | M. Watson, Towson University & NIST J.R. Simpson, Towson University & NIST R. Yan, University of Notre Dame H. Xing, University of Notre Dame S. Bertolazzi, EPFL, Switzerland J. Brivio, EPFL, Switzerland A. Kis, EPFL, Switzerland A.R. Hight-Walker, NIST |
| Correspondent: | Click to Email |
We report temperature and power dependent photoluminescence (PL) of molybdenum disulphide (MoS2). Mechanical exfoliation of MoS2, from bulk provides single-layer flakes which are then transferred either to sapphire substrates or suspended over holes in Si/Si 3 N 4 . We measure temperature dependence from ≈ 100K to 400K and power dependence from ≈ 6μW to ≈ 7mW using an Argon laser at 514.5nm and a HeNe laser at 632.8 nm. The PL spectrum exhibits a main exitonic peak(A) at ≈ 1.87eV which consist of both neutral excitons and charged trions (A- or A+) [1]. The A exciton peak and the A- exciton peak redshift and broaden with increasing temperature and power. Along with the A peak, we observe a lower energy bound exciton (BE) that is likely related to defects. The BE,a broad peak centred at ≈ 1.7eV, linearly redshifts and narrows with increasing power. The power dependence of both the main and bound peak saturates above 0.5mW. Raman temperature and power dependence will also be discussed [2].
[1] KF. Mak et al. Nat. Mat 12,207(2013)
[2] R.Yan and J.R.Simpson, S. Bertolazzi and J. Brivio, M. Watson, X.Wu and A. Kis, T.Luo, H.G.Xing, A.R. Hight Walker, ACS Nano 8,1 (2013)