US 11,917,919 B2
Electret
Noriyuki Matsushita, Kariya (JP); Yoshihiro Kozawa, Kariya (JP); Kazuhiko Kanoh, Kariya (JP); and Yumi Tanaka, Tokyo (JP)
Assigned to DENSO CORPORATION, Kariya (JP); and TOKYO UNIVERSITY OF SCIENCE FOUNDATION, Tokyo (JP)
Filed by DENSO CORPORATION, Kariya (JP); and TOKYO UNIVERSITY OF SCIENCE FOUNDATION, Tokyo (JP)
Filed on Dec. 9, 2020, as Appl. No. 17/116,099.
Claims priority of application No. 2019-225735 (JP), filed on Dec. 13, 2019; and application No. 2020-164898 (JP), filed on Sep. 30, 2020.
Prior Publication US 2021/0184100 A1, Jun. 17, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H10N 30/85 (2023.01); H10N 30/30 (2023.01); H10N 30/853 (2023.01); H10N 30/50 (2023.01); H01G 7/06 (2006.01); H01G 7/02 (2006.01); H10N 30/045 (2023.01)
CPC H10N 30/852 (2023.02) [H01G 7/025 (2013.01); H01G 7/026 (2013.01); H01G 7/06 (2013.01); H10N 30/30 (2023.02); H10N 30/50 (2023.02); H10N 30/853 (2023.02); H10N 30/045 (2023.02)] 9 Claims
OG exemplary drawing
 
1. An electret comprising a substrate and an electret layer formed above a surface of the substrate, wherein
the electret is a composite metal compound containing two or more different metal elements and is obtained by subjecting a thin film mainly composed of an inorganic dielectric material having a bandgap energy of 4 eV or more to a polarization treatment.