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Title: Widely bandgap tunable amorphous Cd–Ga–O oxide semiconductors exhibiting electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}

Abstract

Amorphous oxide semiconductors exhibit large electron mobilities; however, their bandgaps are either too large for solar cells or too small for deep ultraviolet applications depending on the materials system. Herein, we demonstrate that amorphous Cd–Ga–O semiconductors display bandgaps covering the entire 2.5–4.3 eV region while maintaining large electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}. The band alignment diagram obtained by ultraviolet photoemission spectroscopy and the bandgap values reveal that these semiconductors form type-II heterojunctions with p-type Cu{sub 2}O, which is suitable for solar cells and solar-blind ultraviolet sensors.

Authors:
 [1]; ;  [2]; ;  [3];  [4];  [5];  [4];  [5];  [5]
  1. Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510 (Japan)
  2. Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510 (Japan)
  3. Division of Material and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)
  4. Materials and Structures Laboratory, Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)
  5. (Japan)
Publication Date:
OSTI Identifier:
22412696
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMORPHOUS STATE; COPPER OXIDES; ELECTRON MOBILITY; EMISSION SPECTROSCOPY; ENERGY GAP; EV RANGE; HETEROJUNCTIONS; PHOTOELECTRON SPECTROSCOPY; P-TYPE CONDUCTORS; SENSORS; SOLAR CELLS; ULTRAVIOLET RADIATION

Citation Formats

Yanagi, Hiroshi, E-mail: hyanagi@yamanashi.ac.jp, Sato, Chiyuki, Kimura, Yota, Suzuki, Issei, Omata, Takahisa, Kamiya, Toshio, Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Hosono, Hideo, Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, and Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503. Widely bandgap tunable amorphous Cd–Ga–O oxide semiconductors exhibiting electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}. United States: N. p., 2015. Web. doi:10.1063/1.4913691.
Yanagi, Hiroshi, E-mail: hyanagi@yamanashi.ac.jp, Sato, Chiyuki, Kimura, Yota, Suzuki, Issei, Omata, Takahisa, Kamiya, Toshio, Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Hosono, Hideo, Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, & Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503. Widely bandgap tunable amorphous Cd–Ga–O oxide semiconductors exhibiting electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}. United States. doi:10.1063/1.4913691.
Yanagi, Hiroshi, E-mail: hyanagi@yamanashi.ac.jp, Sato, Chiyuki, Kimura, Yota, Suzuki, Issei, Omata, Takahisa, Kamiya, Toshio, Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Hosono, Hideo, Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, and Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503. Mon . "Widely bandgap tunable amorphous Cd–Ga–O oxide semiconductors exhibiting electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}". United States. doi:10.1063/1.4913691.
@article{osti_22412696,
title = {Widely bandgap tunable amorphous Cd–Ga–O oxide semiconductors exhibiting electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}},
author = {Yanagi, Hiroshi, E-mail: hyanagi@yamanashi.ac.jp and Sato, Chiyuki and Kimura, Yota and Suzuki, Issei and Omata, Takahisa and Kamiya, Toshio and Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 and Hosono, Hideo and Materials Research Center for Element Strategy, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 and Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-16, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503},
abstractNote = {Amorphous oxide semiconductors exhibit large electron mobilities; however, their bandgaps are either too large for solar cells or too small for deep ultraviolet applications depending on the materials system. Herein, we demonstrate that amorphous Cd–Ga–O semiconductors display bandgaps covering the entire 2.5–4.3 eV region while maintaining large electron mobilities ≥10 cm{sup 2 }V{sup −1 }s{sup −1}. The band alignment diagram obtained by ultraviolet photoemission spectroscopy and the bandgap values reveal that these semiconductors form type-II heterojunctions with p-type Cu{sub 2}O, which is suitable for solar cells and solar-blind ultraviolet sensors.},
doi = {10.1063/1.4913691},
journal = {Applied Physics Letters},
number = 8,
volume = 106,
place = {United States},
year = {Mon Feb 23 00:00:00 EST 2015},
month = {Mon Feb 23 00:00:00 EST 2015}
}