US 12,391,880 B2
Quantum dot and method of producing the same; and wavelength converting member, lighting member, back light unit, and display device using quantum dot
Yuko Ogura, Fukuoka (JP); Yuka Takamizuma, Fukuoka (JP); Kazunori Iida, Fukuoka (JP); Emi Tsutsumi, Fukuoka (JP); Masanori Tanaka, Fukuoka (JP); and Soichiro Nikata, Fukuoka (JP)
Assigned to TOPPAN INC., Tokyo (JP)
Filed by NS MATERIALS INC., Fukuoka (JP)
Filed on Nov. 3, 2023, as Appl. No. 18/386,884.
Application 18/386,884 is a continuation of application No. 17/405,687, filed on Aug. 18, 2021, granted, now 11,845,890.
Application 17/405,687 is a continuation of application No. 16/754,578, granted, now 11,124,703, issued on Sep. 21, 2021, previously published as PCT/JP2018/038038, filed on Oct. 12, 2018.
Claims priority of application No. 2017-198667 (JP), filed on Oct. 12, 2017.
Prior Publication US 2024/0124774 A1, Apr. 18, 2024
Int. Cl. C09K 11/88 (2006.01); C09K 11/02 (2006.01); F21V 9/30 (2018.01); B82Y 20/00 (2011.01); B82Y 40/00 (2011.01)
CPC C09K 11/883 (2013.01) [C09K 11/025 (2013.01); F21V 9/30 (2018.02); B82Y 20/00 (2013.01); B82Y 40/00 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method of producing a quantum dot comprising:
synthesizing copper chalcogenide as a precursor from an organic copper compound or an inorganic copper compound, and an organic chalcogen compound; and synthesizing a quantum dot free of cadmium using the copper chalcogenide precursor,
wherein the quantum dot contains zinc and selenium, or zinc and selenium and sulfur,
wherein the quantum dot has a core-shell structure containing a nanocrystal core and a shell that covers a surface of the nanocrystal core,
wherein ligands are placed on a surface of the quantum dot, and
wherein the quantum dot has a fluorescence FWHM of 25 nm or less and has a fluorescence quantum yield of 50% or more.