Open AccessRecord-High-Performance Hydrogenated In–Ga–Zn–O Flexible Schottky Diodes
Author(s) -
Yusaku Magari,
Summan Aman,
Daichi Koretomo,
Kentaro Masuda,
Kenta Shimpo,
Hisao Makino,
Mutsumi Kimura,
Mamoru Furuta
Publication year - 2020
Publication title -
acs applied materials and interfaces
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.0c12638
Subject(s) - materials science , schottky barrier , schottky diode , x ray photoelectron spectroscopy , substrate (aquarium) , band gap , optoelectronics , analytical chemistry (journal) , diode , chemistry , oceanography , physics , nuclear magnetic resonance , chromatography , geology
High-performance In-Ga-Zn-O (IGZO) Schottky diodes (SDs) were fabricated using hydrogenated IGZO (IGZO:H) at a maximum process temperature of 150 °C. IGZO:H was prepared by Ar + O 2 + H 2 sputtering. IGZO:H SDs on a glass substrate exhibited superior electrical properties with a very high rectification ratio of 3.8 × 10 10 , an extremely large Schottky barrier height of 1.17 eV, and a low ideality factor of 1.07. It was confirmed that the hydrogen incorporated during IGZO:H deposition increased the band gap energy from 3.02 eV (IGZO) to 3.29 eV (IGZO:H). Thus, it was considered that the increase in band gap energy (decrease in electron affinity) of IGZO:H contributed to the increase in the Schottky barrier height of the SDs. Angle-resolved hard X-ray photoelectron spectroscopy analysis revealed that oxygen vacancies in IGZO:H were much fewer than those in IGZO, especially in the region near the film surface. Moreover, it was found that the density of near-conduction band minimum states in IGZO:H was lower than that in IGZO. Therefore, IGZO:H played a key role in improving the Schottky interface quality, namely, the increase of Schottky barrier height, decrease of oxygen vacancies, and reduction of near-conduction band minimum states. Finally, we fabricated a flexible IGZO:H SD on a poly(ethylene naphthalate) substrate, and it exhibited record electrical properties with a rectification ratio of 1.7 × 10 9 , Schottky barrier height of 1.12 eV, and ideality factor of 1.10. To the best of our knowledge, both the IGZO:H SDs formed on glass and poly(ethylene naphthalate) substrates achieved the best performance among the IGZO SDs reported to date. The proposed method successfully demonstrated great potential for future flexible electronic applications.