Abstract
Composition and phase specific 2D transition metal dichalogenides (2D TMDs) with a controlled electronic and chemical structure are essential for future electronics. While alloying allows bandgap tunability, heterostructure formation creates atomically sharp electronic junctions. Herein, the formation of lateral heterostructures from quaternary 2D TMD alloys, by thermal annealing, is demonstrated. Phase separation is observed through photoluminescence and Raman spectroscopy, and the sharp interface of the lateral heterostructure is examined via scanning transmission electron microscopy. The composition-dependent transformation is caused by existence of miscibility gap in the quaternary alloys. The phase diagram displaying the miscibility gap is obtained from the reciprocal solution model based on density functional theory and verified experimentally. The experiments show direct evidence of composition-driven heterostructure formation in 2D atomic layer systems.
Original language | English |
---|---|
Article number | 1804218 |
Journal | Advanced Materials |
Volume | 30 |
Issue number | 45 |
DOIs | |
State | Published - Nov 8 2018 |
Funding
S.S. and J.A.H. contributed equally to this work. This work was supported by FAME, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA, and the Air Force Office of Scientific Research under award number FA9550-18-1-0072 C.S.T acknowledges SERB India-Ramanujan Fellowship. Microscopy research performed as part of a user proposal at Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences (CNMS), which is a U.S. Department of Energy, Office of Science User Facility (J.A.H. and J.C.I.). Computations (A.K.) and theoretical analysis (X.Y. and B.I.Y.) were supported by the U.S. DOE (DE-SC0012547) and the R. Welch Foundation (C-1590). S.S. and J.A.H. contributed equally to this work. This work was supported by FAME, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA, and the Air Force Office of Scientific Research under award number FA9550-18-1-0072 C.S.T acknowledges SERB India-Ramanujan Fellowship. Microscopy research performed as part of a user proposal at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences (CNMS), which is a U.S. Department of Energy, Office of Science User Facility (J.A.H. and J.C.I.). Computations (A.K.) and theoretical analysis (X.Y. and B.I.Y.) were supported by the U.S. DOE (DE-SC0012547) and the R. Welch Foundation (C-1590).
Keywords
- alloys
- density functional theory
- heterostructures
- phase diagrams
- phase stability
- scanning transmission electron microscopy