Patent Number: 6,254,740

Title: Sputtering method of producing and electroluminescent device with improved blue color purity

Abstract: Disclosed is a method of producing an electroluminescent (EL) device having a CaGa.sub.2 S.sub.4 :Ce luminescent layer. The ratio of the X-ray diffraction peak intensity I.sub.2 for the (200) reflection of CaS to the X-ray diffraction peak intensity I.sub.1 for the (400) reflection of CaGa.sub.2 S.sub.4 as appearing in the X-ray diffraction spectrum for the luminescent layer, I.sup.2 /I.sub.1, is 0.1 or less. The amount of the impurity CaS in the luminescent layer is reduced. The EL device produces blue emission with high purity.

Inventors: Kato; Akira (Kariya, JP), Katayama; Masayuki (Handa, JP), Ito; Nobuei (Chiryu, JP), Hattori; Tadashi (Okazaki, JP)

Assignee: Nippondenso Co., Ltd.

International Classification: C09K 11/77 (20060101); H05B 33/14 (20060101); C23C 014/34 ()

Expiration Date: 07/03/2018