PMID- 26125321
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20151123
LR  - 20150728
IS  - 1936-086X (Electronic)
IS  - 1936-0851 (Linking)
VI  - 9
IP  - 7
DP  - 2015 Jul 28
TI  - Reversible Semiconducting-to-Metallic Phase Transition in Chemical Vapor 
      Deposition Grown Monolayer WSe2 and Applications for Devices.
PG  - 7383-91
LID - 10.1021/acsnano.5b02399 [doi]
AB  - Two-dimensional (2D) semiconducting monolayer transition metal dichalcogenides 
      (TMDCs) have stimulated lots of interest because they are direct bandgap 
      materials that have reasonably good mobility values. However, contact between 
      most metals and semiconducting TMDCs like 2H phase WSe2 are highly resistive, 
      thus degrading the performance of field effect transistors (FETs) fabricated with 
      WSe2 as active channel materials. Recently, a phase engineering concept of 2D 
      MoS2 materials was developed, with improved device performance. Here, we applied 
      this method to chemical vapor deposition (CVD) grown monolayer 2H-WSe2 and 
      demonstrated semiconducting-to-metallic phase transition in atomically thin WSe2. 
      We have also shown that metallic phase WSe2 can be converted back to 
      semiconducting phase, demonstrating the reversibility of this phase transition. 
      In addition, we fabricated FETs based on these CVD-grown WSe2 flakes with 
      phase-engineered metallic 1T-WSe2 as contact regions and intact semiconducting 
      2H-WSe2 as active channel materials. The device performance is substantially 
      improved with metallic phase source/drain electrodes, showing on/off current 
      ratios of 10(7) and mobilities up to 66 cm(2)/V.s for monolayer WSe2. These 
      results further suggest that phase engineering can be a generic strategy to 
      improve device performance for many kinds of 2D TMDC materials.
FAU - Ma, Yuqiang
AU  - Ma Y
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Liu, Bilu
AU  - Liu B
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Zhang, Anyi
AU  - Zhang A
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Chen, Liang
AU  - Chen L
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Fathi, Mohammad
AU  - Fathi M
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Shen, Chenfei
AU  - Shen C
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Abbas, Ahmad N
AU  - Abbas AN
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Ge, Mingyuan
AU  - Ge M
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Mecklenburg, Matthew
AU  - Mecklenburg M
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
FAU - Zhou, Chongwu
AU  - Zhou C
AD  - Department of Electrical Engineering, University of Southern California, Los 
      Angeles, California 90089, United States.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20150630
PL  - United States
TA  - ACS Nano
JT  - ACS nano
JID - 101313589
OTO - NOTNLM
OT  - contact
OT  - field effect transistor
OT  - mobility
OT  - phase engineering
OT  - transition metal dichalcogenides
OT  - tungsten diselenide
OT  - two-dimensional materials
EDAT- 2015/07/01 06:00
MHDA- 2015/07/01 06:01
CRDT- 2015/07/01 06:00
PHST- 2015/07/01 06:00 [entrez]
PHST- 2015/07/01 06:00 [pubmed]
PHST- 2015/07/01 06:01 [medline]
AID - 10.1021/acsnano.5b02399 [doi]
PST - ppublish
SO  - ACS Nano. 2015 Jul 28;9(7):7383-91. doi: 10.1021/acsnano.5b02399. Epub 2015 Jun 
      30.