[13a-A303-1~8] 13.8 Optical properties and light-emitting devices

[13a-A303-5] Synthesis and optical properties of Zn(Te_1-xS_x) quantum dots

〇Satoshi Tsukuda¹, Haruko Inayoshi¹, Masao Kita², Takahisa Omata¹ (1.IMRAM, Tohoku Univ., 2.NIT, Toyama college)

Keywords:quantum dot, alloy, phosphor

CdSe-based quantum dots (QDs) have been applied as green and red phosphors for backlight downconversion in liquid crystal displays because of their excellent light emission properties such as tunable emission wavelength, high quantum yield and narrow emission band width. However, alternatives to CdSe-based QDs are strongly desired owing to cadmium toxicity. Recently, our group has theoretically indicated that Zn(Te,Se) and Zn(Te,S) alloyed QDs are good candidates as cadmium-free and green and red QD-phosphors. Zn(Te_1-xSe_x)/ZnS core/shell QDs have already synthesized and exhibited narrow green band emission (full width at half maximum: FWHM = 30 nm). Although Zn(Te_1-xS_x) QD is promising material as a cadmium free red phosphor, the red emission from Zn(Te_1-xS_x) QDs has not been realised yet. In this study, we synthesized Zn(Te_1-xS_x) QDs with various composition x and particle sizes. The optical properties of Zn(Te_1-xS_x) QDs were evaluated in terms of the optical gap and emission energy depending on both particle size and their composition, x.