TY - JOUR
T1 - Anomalous Conductivity Switch Observed in Treated Hafnium Diselenide Transistors
AU - Albagami, Malak
AU - Alrasheed, Abdullah
AU - Alharbi, Mervat
AU - Alhazmi, Abrar
AU - Wong, Kin
AU - Qasem, Hussam
AU - Alodan, Sarah
AU - Alolaiyan, Olaiyan
AU - Wang, Kang L.
AU - Amer, Moh R.
N1 - Funding Information:
M.A. and A.A. contributed equally to this work. This research was financially supported by King Abdulaziz City for Science and Technology (KACST) through the Center of Excellence for Green Nanotechnologies (CEGN) under the technical leaders program part of NTP.
Publisher Copyright:
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Layered hafnium diselenide (HfSe2) is an emerging Van der Waals semiconductor in which a hafnium layer is sandwiched between two selenium layers. Owning to its indirect band gap with magnitudes close to silicon's band gap and high predicted carrier mobility, hafnium diselenide material is a strong candidate for device applications. Here, the effect of laser treatment on 2H- HfSe2 devices is shown in ambient conditions using µ-Raman spectroscopy. It is shown that an emerging Raman peak evolves with increasing laser exposure time. It is also shown that top-down fabricated 2H-HfSe2 devices exhibit an anomalous p-type behavior post laser treatment, with Ion/Ioff ratio as high as 103. This anomalous conductivity change can be observed after thermal and electrical annealing. For bottom-up devices, it is observed that p-type conductivity with remarkable Ion/Ioff ratio reaching 104. This conductivity switch can also be shown on 1T-HfSe2 devices post laser irradiation and high Vds bias treatments. Based on the circuit model, this conductivity switch is attributed to contact doping caused by an increase in the Schottky barrier height at each contact, which shifts the Fermi energy closer to the valance band. These results demonstrate a unique conductivity switching mechanism for HfSe2-FET devices.
AB - Layered hafnium diselenide (HfSe2) is an emerging Van der Waals semiconductor in which a hafnium layer is sandwiched between two selenium layers. Owning to its indirect band gap with magnitudes close to silicon's band gap and high predicted carrier mobility, hafnium diselenide material is a strong candidate for device applications. Here, the effect of laser treatment on 2H- HfSe2 devices is shown in ambient conditions using µ-Raman spectroscopy. It is shown that an emerging Raman peak evolves with increasing laser exposure time. It is also shown that top-down fabricated 2H-HfSe2 devices exhibit an anomalous p-type behavior post laser treatment, with Ion/Ioff ratio as high as 103. This anomalous conductivity change can be observed after thermal and electrical annealing. For bottom-up devices, it is observed that p-type conductivity with remarkable Ion/Ioff ratio reaching 104. This conductivity switch can also be shown on 1T-HfSe2 devices post laser irradiation and high Vds bias treatments. Based on the circuit model, this conductivity switch is attributed to contact doping caused by an increase in the Schottky barrier height at each contact, which shifts the Fermi energy closer to the valance band. These results demonstrate a unique conductivity switching mechanism for HfSe2-FET devices.
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U2 - 10.1002/aelm.201901246
DO - 10.1002/aelm.201901246
M3 - Article
AN - SCOPUS:85083050651
VL - 6
JO - Advanced Electronic Materials
JF - Advanced Electronic Materials
SN - 2199-160X
IS - 5
M1 - 1901246
ER -