Band offset and electron affinity of MBE-grown SnSe2
Abstract
SnSe2 is currently considered a potential two-dimensional material that can form a near-broken gap heterojunction in a tunnel field-effect transistor due to its large electron affinity which is experimentally confirmed in this letter. With the results from internal photoemission and angle-resolved photoemission spectroscopy performed on Al/Al2O3/SnSe2/GaAs and SnSe2/GaAs test structures where SnSe2 is grown on GaAs by molecular beam epitaxy, we ascertain a (5.2 ± 0.1) eV electron affinity of SnSe2. The band offset from the SnSe2 Fermi level to the Al2O3 conduction band minimum is found to be (3.3 ± 0.05) eV and SnSe2 is seen to have a high level of intrinsic electron (n-type) doping with the Fermi level positioned at about 0.2 eV above its conduction band minimum. It is concluded that the electron affinity of SnSe2 is larger than that of most semiconductors and can be combined with other appropriate semiconductors to form near broken-gap heterojunctions for the tunnel field-effect transistor that can potentially achieve high on-currents.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 22, 2018
- Source ID
- 10.1063/1.5016183
Entities
People
- Angela R. Hight Walker
- David J. Gundlach
- Edward B. Lochocki
- Guangjun Cheng
- Huai-hsun Lien
- Huili Grace Xing
- Jacek Furdyna
- Kyle. M. Shen
- Malgorzata Dobrowolska
- Mingda (oscar) Li
- Nam V. Nguyen
- Qin Zhang
- Rusen Yan
- Suresh Vishwanath
- Xinyu Liu
Organizations
- Air Force Office of Scientific Research
- Cornell University
- National Institute of Standards and Technology
- National Science Foundation
- Theiss Research
- University of Notre Dame