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High‐Mobility and Air‐Stable Amorphous Semiconductor Composed of Earth‐Abundant Elements: Amorphous Zinc Oxysulfide
Author(s) -
Zhu Yuting,
Yamazaki Takanori,
Chen Zhen,
Hirose Yasushi,
Nakao Shoichiro,
Harayama Isao,
Sekiba Daiichiro,
Hasegawa Tetsuya
Publication year - 2020
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201900602
Subject(s) - materials science , amorphous solid , thin film transistor , semiconductor , electron mobility , thin film , optoelectronics , pulsed laser deposition , zinc , analytical chemistry (journal) , nanotechnology , layer (electronics) , crystallography , metallurgy , chemistry , chromatography
Amorphous oxide semiconductors have been widely studied as key materials for flat panel displays and flexible electronics devices. Recently, it has been reported that an amorphous mixed‐anion semiconductor consisting of only earth‐abundant elements, zinc oxynitride, shows high electron mobility and good performance as the channel layer of a thin‐film transistor. However, amorphous zinc oxynitrides are unstable in air. It is demonstrated that another type of earth‐abundant amorphous mixed‐anion semiconductor, amorphous zinc oxysulfide (a‐ZnO x S y ) thin film, exhibits electron mobilities comparable to those of conventional amorphous oxide semiconductors, in addition to good chemical stability under ambient conditions. a‐ZnO x S y thin films with a wide compositional range are fabricated through pulsed laser deposition, by alternately depositing ZnO and ZnS. Their transport properties can be controlled by adjusting the laser fluence and anion composition, and conductive a‐ZnO x S y thin films (≈0.30 ≤ y /( x + y ) ≤ ≈0.35) show high electron Hall mobilities of 10–15 cm 2 V −1 s −1 at a carrier density of < ≈10 18 cm −3 . Furthermore, the Hall mobility can be maintained in air for at least 12 months. An a‐ZnO x S y thin‐film transistor with a bottom‐gate and top contact configuration shows clear field effect transistor behavior, although its performance is so far moderate.