TY - JOUR
T1 - Sputter deposition of ZnO-AlN pseudo-binary amorphous alloys with tunable band gaps in the deep ultraviolet region
AU - Urakawa, Seiichi
AU - Magdy, Wafaa
AU - Wada, Yoshiharu
AU - Narishige, Ryota
AU - Kaneshima, Kentaro
AU - Yamashita, Naoto
AU - Okumura, Takamasa
AU - Kamataki, Kunihiro
AU - Koga, Kazunori
AU - Shiratani, Masaharu
AU - Itagaki, Naho
N1 - Publisher Copyright:
© 2024 The Author(s). Published by IOP Publishing Ltd
PY - 2024/6/1
Y1 - 2024/6/1
N2 - ZnO-AlN pseudo-binary amorphous alloys (a-ZAON hereinafter) with tunable band gaps in the deep ultraviolet (DUV) region have been synthesized using magnetron sputtering. The miscibility gap between ZnO and AlN has been overcome using room-temperature sputtering deposition, leveraging the rapid quenching abilities of sputtered particles to fabricate metastable but single-phase alloys. X-ray diffraction patterns and optical transmittance spectra revealed that the synthesized films with chemical composition ratios of [Zn]/([Zn] + [Al]) = 0.24-0.79 likely manifested as single-phase of a-ZAON films. Despite their amorphous structures, these films presented direct band gaps of 3.4-5.8 eV and thus high optical absorption coefficients (105 cm−1). Notably, the observed values adhered to Vegard’s law for crystalline ZnO-AlN systems, implying that the a-ZAON films were solid solution alloys with atomic-level mixing. Furthermore, atomic force microscopy analyses revealed smooth film surfaces with root-mean-square roughness of 0.8-0.9 nm. Overall, the wide-ranging band gap tunability, high absorption coefficients, amorphous structures, surface smoothness, and low synthesis temperatures of a-ZAON films position them as promising materials for use in DUV optoelectronic devices and power devices fabricated using large-scale glass and flexible substrates.
AB - ZnO-AlN pseudo-binary amorphous alloys (a-ZAON hereinafter) with tunable band gaps in the deep ultraviolet (DUV) region have been synthesized using magnetron sputtering. The miscibility gap between ZnO and AlN has been overcome using room-temperature sputtering deposition, leveraging the rapid quenching abilities of sputtered particles to fabricate metastable but single-phase alloys. X-ray diffraction patterns and optical transmittance spectra revealed that the synthesized films with chemical composition ratios of [Zn]/([Zn] + [Al]) = 0.24-0.79 likely manifested as single-phase of a-ZAON films. Despite their amorphous structures, these films presented direct band gaps of 3.4-5.8 eV and thus high optical absorption coefficients (105 cm−1). Notably, the observed values adhered to Vegard’s law for crystalline ZnO-AlN systems, implying that the a-ZAON films were solid solution alloys with atomic-level mixing. Furthermore, atomic force microscopy analyses revealed smooth film surfaces with root-mean-square roughness of 0.8-0.9 nm. Overall, the wide-ranging band gap tunability, high absorption coefficients, amorphous structures, surface smoothness, and low synthesis temperatures of a-ZAON films position them as promising materials for use in DUV optoelectronic devices and power devices fabricated using large-scale glass and flexible substrates.
KW - amorphous
KW - chemical composition
KW - pseudo-binary alloys
KW - semiconductor
KW - sputtering
KW - ultra-wide band gap
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U2 - 10.1088/2053-1591/ad4f57
DO - 10.1088/2053-1591/ad4f57
M3 - Article
AN - SCOPUS:85195699940
SN - 2053-1591
VL - 11
JO - Materials Research Express
JF - Materials Research Express
IS - 6
M1 - 065901
ER -