(19) TZZ ¥_T (11) EP 2 853 578 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C09K 11/02 (2006.01) C09K 11/56 (2006.01) 30.08.2017 Bulletin 2017/35 C09K 11/61 (2006.01) C09K 11/70 (2006.01) C09K 11/88 (2006.01) B82Y 20/00 (2011.01) (2011.01) (21) Application number: 14185782.1 B82Y 40/00 (22) Date of filing: 22.09.2014 (54) Nanocrystal particles and processes for synthesizing the same Nanokristallpartikel und Verfahren zur Synthetisierung davon Particules de nanocristal et procédés permettant de les synthétiser (84) Designated Contracting States: • Kim, Taekhoon AL AT BE BG CH CY CZ DE DK EE ES FI FR GB Hwaseong-si, GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO Gyeonggi-do (KR) PL PT RO RS SE SI SK SM TR (74) Representative: Mullen, Lee Bryan et al (30) Priority: 26.09.2013 KR 20130114601 Elkington and Fife LLP 18.09.2014 KR 20140124542 Thavies Inn House 3-4 Holborn Circus (43) Date of publication of application: London EC1N 2HA (GB) 01.04.2015 Bulletin 2015/14 (56) References cited: (73) Proprietor: Samsung Electronics Co., Ltd. WO-A1-01/25316 WO-A1-2012/112120 Gyeonggi-do 443-742 (KR) WO-A2-2006/116337 WO-A2-2012/111009 US-A1- 2007 125 984 (72) Inventors: • Kim, Hyunki • CHEN ZHONG ET AL: "Photoluminescence Suwon-si, spectra of ZnS:X-(X=F and I) nanoparticles Gyeonggi-do (KR) synthesized via a solid-state reac", OPTICAL • Jun, Shin Ae MATERIALS, vol. 36, no. 6, 28 February 2014 Seongnam-si, (2014-02-28), pages 1007-1012, XP028627648, Gyeonggi-do (KR) ISSN: 0925-3467, DOI: • Kim,Yongwook 10.1016/J.OPTMAT.2014.01.002 Hwaseong-si, • K MANZOOR ET AL: "Synthesis and Gyeonggi-do (KR) photoluminescent properties of ZnS • Kim, Tae Gon nanocrystals doped with copper and halogen", Hwaseong-si, MATERIALS CHEMISTRY AND PHYSICS, vol. 82, Gyeonggi-do (KR) no. 3, 1 December 2003 (2003-12-01), pages • Won, Yuho 718-725, XP055169040, ISSN: 0254-0584, DOI: Seoul (KR) 10.1016/S0254-0584(03)00366-3 • Jang, Eun Joo Suwon-si, Gyeonggi-do (KR) • Jang, Hyo Sook Suwon-si, Gyeonggi-do (KR) Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 2 853 578 B1 Printed by Jouve, 75001 PARIS (FR) (Cont. next page) EP 2 853 578 B1 • MARSH J H ET AL: "Impurity induced disordering of GaInAs quantum wells with barriers of AlGaInAs or of GaInAsP (MQW waveguides)", INDIUM PHOSPHIDE AND RELATED MATERIALS, 1991., THIRD INTERNATIONAL CON FERENCE. CARDIFF, UK 8-11 APRIL 1991, NEW YORK, NY, USA,IEEE, US, 8 April 1991 (1991-04-08), pages 592-595, XP010038657, DOI: 10.1109/ICIPRM.1991.147446 ISBN: 978-0-87942-626-2 2 EP 2 853 578 B1 Description FIELD OF THE INVENTION 5 [0001] A nanocrystal particle and a process for synthesizing the same are disclosed. BACKGROUND OF THE INVENTION [0002] Unlike bulk materials, nanocrystals may control their physical characteristics (e.g., energy bandgap and melting 10 point) that are known to be an intrinsic property by changing their particle size. For example, a semiconductor nanocrystal (also known as a quantum dot) is a semiconductor material having a crystalline structure of a size of several nanometers. The semiconductor nanocrystal has a very small size so that it has a large surface area per unit volume and may exhibit a quantum confinement effect. Therefore, the semiconductor nanocrystal has different physicochemical characteristics from the bulk material having the same composition. In other words, the nanocrystal may adjust various characteristics 15 by controlling its size. A quantum dot may absorb light from an excitation source to be in an excited state, and may emit energy corresponding to its energy bandgap. [0003] The semiconductor nanocrystal may be synthesized by a vapor deposition method such as metal organic chemical vapor deposition ("MOCVD") and molecular beam epitaxy ("MBE"), or by a wet chemical method of adding a precursor to an organic solvent to grow crystals. In the wet chemical method, organic materials such as a dispersant 20 are coordinated to a surface of the semiconductor crystal during the crystal growth to control the crystal growth. Therefore, the nanocrystals produced by the wet chemical method usually have a more uniform size and shape than those produced by the vapor deposition method. [0004] Semiconductor nanocrystal materials having a core-shell structure may exhibit slightly enhanced quantum efficiency, but a need to develop technologies to enhance qualities (such as quantum efficiency) of the nanocrystals still 25 remains. [0005] US 2007/125984 (A1) discloses a photoluminescent phosphor coated with a coating of oxide. The phosphor comprises (1) an inorganic phosphor chosen from (a) a metal thiogallate phosphor and (b) a metal sulfide phosphor and (2) a coating that comprises at least one layer having at least one oxides. [0006] K Manzoor et al: "Synthesis and photoluminescent properties of ZnS nanocrystals doped with copper and 30 halogen", Materials chemistry and physics, vol 82, no. 3, 2003, pages 718-725 discloses a wet-chemical precipitation method optimised for the synthesis of ZnS nanocrystals doped with Cu+ and halogen. The structure and photo-physics of the crystals was characterized. By controlling the defect chemistry and suitable doping, photo-luminescence emission was tunable. 35 SUMMARY OF THE INVENTION [0007] An embodiment provides semiconductor nanocrystals having enhanced light emitting properties such as a high quantum yield. [0008] Another embodiment provides a process of preparing the semiconductor nanocrystals having enhanced light 40 emitting properties. [0009] In an embodiment, a nanocrystal particle includes at least one semiconductor material and at least one halogen element, and has a core-shell structure including a core of a first semiconductor nanocrystal, and a shell surrounding the core and including a crystalline or amorphous material. The least one halogen element may present as being doped in the particle or as a metal halide. The halogen element may be substituted in the crystalline structure of the particle 45 or may be introduced therein as an interstitial atom. [0010] The at least one halogen element may comprises fluorine (F). [0011] The first semiconductor nanocrystal may include a Group II metal, a Group III metal, a Group IV metal, or a combination thereof, and the crystalline or amorphous material may include at least one metal being different from the metal included in the first semiconductor nanocrystal and being selected from a Group I metal, a Group II metal, a Group 50 III metal, a Group IV metal, or a combination thereof. [0012] For example, the first nanocrystal may be a first semiconductor material, and the crystalline material of the shellmay be a second semiconductor material that is deposited on the core and that isdifferent from thefirst semiconductor material. The halogen element may be included in the core, and/or the halogen element may be present at an interface between 55 the core and the shell, and/or the halogen element may be present in the shell. [0013] The shell may be a multi-layered shell having at least two layers, each of the layers including the same or different crystalline or amorphous materials, and the halogen element may be present in a core region, in an inner shell (i.e., an inner layer of the shell), in an outer shell (i.e., an outer layer of the shell being on the inner layer), at an inte rface 3 EP 2 853 578 B1 between the core and the shell, at an interface between the layers of the shell, or in at least one place of the foregoing. The halogen element may be present in all of the aforementioned regions. [0014] The halogen element may be included in an amount of greater than or equal to about 0.05 % based on a total molar amount of a metal of the core of the nanocrystal particle. The halogen element may be included in an amount of 5 less than or equal to about 200%, for example, less than or equal to about 190%, less than or equal to about 180%, less than or equal to about 170%, less than or equal to about 160%, less than or equal to about 150%, less than or equal to about 140%, less than or equal to about 130%, less than or equal to about 120%, less than or equal to about 110%, or less thanor equal to about 100% basedon a totalmolar amount of themetal of the coreof the nanocrystal particle. [0015] The at least one halogen element may be fluorine, and it may be present in the form of a fluoride including a 10 Group I metal, a fluoride including a Group II metal, a fluoride including a Group III metal, or a combination thereof. [0016] The first semiconductor nanocrystal of the core may include a Group II-VI compound, a Group III-V compound, a Group IV-VI compound, a Group IV compound, or a combination thereof, and the crystalline or amorphous material of the shell may include a Group II-VI compound, a Group III-V compound, a Group IV-VI compound, a Group IV compound, a halogen compound containing a metal, a metal oxide, or a combination thereof.