journal article·2019-07-23

Band Structure Engineering of Layered WSe2 via One-Step Chemical Functionalization

Jun Hong Park, Amritesh Rai, Jeongwoon Hwang, Chenxi Zhang, Iljo Kwak, Steven F. Wolf, Suresh Vishwanath, Xinyu Liu, Malgorzata Dobrowolska, Jacek Furdyna, Huili Grace Xing, Kyeongjae Cho, Sanjay K. Banerjee, Andrew C. Kummel

ACS Nano· Volume 13· Issue 7
Publisher page

Abstract

Chemical functionalization is demonstrated to enhance the p-type electrical performance of two-dimensional (2D) layered tungsten diselenide (WSe2) field-effect transistors (FETs) using a one-step dipping process in an aqueous solution of ammonium sulfide [(NH4)2S(aq)]. Molecularly resolved scanning tunneling microscopy and spectroscopy reveal that molecular adsorption on a monolayer WSe2 surface induces a reduction of the electronic band gap from 2.1 to 1.1 eV and a Fermi level shift toward the WSe2 valence band edge (VBE), consistent with an increase in the density of positive charge carriers. The mechanism of electronic transformation of WSe2 by (NH4)2S(aq) chemical treatment is elucidated using density functional theory calculations which reveal that molecular “SH” adsorption on the WSe2 surface introduces additional in-gap states near the VBE, thereby, inducing a Fermi level shift toward the VBE along with a reduction in the electronic band gap. As a result of the (NH4)2S(aq) chemical treatment, the p-branch ON-currents (ION) of back-gated few-layer ambipolar WSe2 FETs are enhanced by about 2 orders of magnitude, and a ∼6× increase in the hole field-effect mobility is observed, the latter primarily resulting from the p-doping-induced narrowing of the Schottky barrier width leading to an enhanced hole injection at the WSe2/contact metal interface. This (NH4)2S(aq) chemical functionalization technique can serve as a model method to control the electronic band structure and enhance the performance of devices based on 2D layered transition-metal dichalcogenides.
Source: openalex_inverted_index · Quality: baseline

Research context

OpenAlex topics: 2D Materials and Applications · MXene and MAX Phase Materials · Graphene research and applications

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

School of Materials Science and Engineering, Gyeongsang National University, Jinju 52828, Republic of Korea

Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, United States

Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, United States

Department of Materials Science and Engineering, The University of Texas at Dallas, Dallas, Texas 75080, United States

Department of Physics Education, Chonnam National University, Gwangju 61186, Republic of Korea

School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, United States

Physics Department, University of Notre Dame, Notre Dame, Indiana 46556, United States

Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States

Departments of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States

Funding

Defense Advanced Research Projects Agency · Division of Emerging Frontiers in Research and Innovation · Army Research Office · National Research Foundation of Korea · Microelectronics Advanced Research Corporation · Semiconductor Research Corporation · Division of Engineering Education and Centers · Division of Materials Research

References (62)

Show source-provided references
1. 10.1126/science.aah469810.1126/science.aah4698 ↗
2. 10.1038/nature1538710.1038/nature15387 ↗
3. 10.1021/acs.nanolett.5b0108010.1021/acs.nanolett.5b01080 ↗
4. 10.1109/JPROC.2013.225343510.1109/JPROC.2013.2253435 ↗
5. 10.1103/PhysRevB.85.20530210.1103/PhysRevB.85.205302 ↗
6. 10.1038/nnano.2013.27710.1038/nnano.2013.277 ↗
7. 10.1103/PhysRevB.91.04140710.1103/PhysRevB.91.041407 ↗
8. 10.1038/natrevmats.2016.5210.1038/natrevmats.2016.52 ↗
9. 10.1126/science.235.4785.17210.1126/science.235.4785.172 ↗
10. 10.1038/503327a10.1038/503327a ↗
11. 10.1088/0022-3727/49/6/06530410.1088/0022-3727/49/6/065304 ↗
12. 10.1021/jz301673x10.1021/jz301673x ↗
13. 10.1063/1.479912610.1063/1.4799126 ↗
14. 10.1038/nmat408010.1038/nmat4080 ↗
15. 10.1039/C4NR00177J10.1039/C4NR00177J ↗
16. 10.1038/nnano.2017.10010.1038/nnano.2017.100 ↗
17. 10.1088/2053-1583/3/2/02200210.1088/2053-1583/3/2/022002 ↗
18. 10.1021/acs.nanolett.6b0185310.1021/acs.nanolett.6b01853 ↗
19. 10.1021/acs.nanolett.5b0472410.1021/acs.nanolett.5b04724 ↗
20. 10.1007/s12274-016-1232-510.1007/s12274-016-1232-5 ↗
21. 10.1038/ncomms629010.1038/ncomms6290 ↗
22. 10.1088/0957-4484/25/37/37570310.1088/0957-4484/25/37/375703 ↗
23. 10.1063/1.482489310.1063/1.4824893 ↗
24. 10.1063/1.146770210.1063/1.1467702 ↗
25. 10.1088/0022-3727/43/4/04540410.1088/0022-3727/43/4/045404 ↗
26. 10.1103/PhysRevLett.109.03550310.1103/PhysRevLett.109.035503 ↗
27. 10.1021/nl503251h10.1021/nl503251h ↗
28. 10.1021/acs.nanolett.5b0506610.1021/acs.nanolett.5b05066 ↗
29. 10.1021/acsnano.6b0252110.1021/acsnano.6b02521 ↗
30. 10.1021/acs.nanolett.6b0039010.1021/acs.nanolett.6b00390 ↗
31. 10.1021/nn504784410.1021/nn5047844 ↗
32. 10.1021/ja503332710.1021/ja5033327 ↗
33. 10.1021/nl400044m10.1021/nl400044m ↗
34. 10.1021/acs.nanolett.5b0031410.1021/acs.nanolett.5b00314 ↗
35. 10.1002/aelm.20160035810.1002/aelm.201600358 ↗
36. 10.1109/TED.2016.255414910.1109/TED.2016.2554149 ↗
37. 10.1021/acsnano.5b0440010.1021/acsnano.5b04400 ↗
38. 10.1021/acsnano.5b0696010.1021/acsnano.5b06960 ↗
39. 10.1126/science.aad211410.1126/science.aad2114 ↗
40. 10.1021/nl304777e10.1021/nl304777e ↗
41. 10.1021/acsnano.5b0461110.1021/acsnano.5b04611 ↗
42. 10.1021/nn500992910.1021/nn5009929 ↗
43. 10.1021/acs.nanolett.5b0066810.1021/acs.nanolett.5b00668 ↗
44. 10.1063/1.365175410.1063/1.3651754 ↗
45. 10.1021/nn203393d10.1021/nn203393d ↗
46. 10.1021/acsami.7b1916910.1021/acsami.7b19169 ↗
47. 10.1038/nmat296810.1038/nmat2968 ↗
48. 10.1021/acsnano.5b0769810.1021/acsnano.5b07698 ↗
49. 10.1016/0022-1902(62)80178-X10.1016/0022-1902(62)80178-X ↗
50. 10.1016/S0927-7757(02)00363-110.1016/S0927-7757(02)00363-1 ↗
51. 10.1116/1.498222310.1116/1.4982223 ↗
52. 10.1103/PhysRevB.48.1749310.1103/PhysRevB.48.17493 ↗
53. 10.1021/ja049113z10.1021/ja049113z ↗
54. 10.1038/ncomms866610.1038/ncomms8666 ↗
55. 10.1088/2053-1583/2/3/03400410.1088/2053-1583/2/3/034004 ↗
56. 10.1021/acs.nanolett.5b0196810.1021/acs.nanolett.5b01968 ↗
57. 10.1016/j.commatsci.2012.09.00610.1016/j.commatsci.2012.09.006 ↗
58. 10.1103/PhysRevLett.119.04610110.1103/PhysRevLett.119.046101 ↗
59. 10.1021/acsami.8b1006310.1021/acsami.8b10063 ↗
60. 10.1039/c3nr03052k10.1039/c3nr03052k ↗
61. 10.1063/1.482040810.1063/1.4820408 ↗
62. 10.3390/cryst808031610.3390/cryst8080316 ↗