CAJ | 학술논문

采用高温固相法合成出系列黄绿色Sr_(1-y)Eu_ySi_2O_(2-z)N_(2+2z/3) 荧光材料,进行了光学性质表征并探索了其在LED上的应用.在Eu~(2+)掺杂浓度为0~0.200范围内,所合成的化合物为系列色坐标可调的黄绿光-黄光连续固溶体,在250～500 nm具有高的激发效率,激发和发射光谱位置及其发射强度随Eu~(2+)浓度改变产生规律性变化;利用光谱理论系统研究了Eu~(2+)的最低5d吸收能级、5d轨道重心移动、晶体场分裂和Stokes位移对激发和发射光谱位置、半峰全宽和荧光寿命的影响及其相互关系.该类荧光材料在77～425 K具有良好的温度特性,425 K时的发射强度为77 K的58%左右.首次将它们和近紫外LED(～400 nm)、蓝光LED(～460 nm)封装成高亮度黄绿光和黄光LED以及白光LED,发光效率高达19 lm/W,这些封装的LED的发光性能也随着Eu~(2+)浓度,以及粉胶比例变化而呈规律性变化.
채용고온고상법합성출계렬황록색Sr_(1-y)Eu_ySi_2O_(2-z)N_(2+2z/3) 형광재료,진행료광학성질표정병탐색료기재LED상적응용.재Eu~(2+)참잡농도위0~0.200범위내,소합성적화합물위계렬색좌표가조적황록광-황광련속고용체,재250～500 nm구유고적격발효솔,격발화발사광보위치급기발사강도수Eu~(2+)농도개변산생규률성변화;이용광보이론계통연구료Eu~(2+)적최저5d흡수능급、5d궤도중심이동、정체장분렬화Stokes위이대격발화발사광보위치、반봉전관화형광수명적영향급기상호관계.해류형광재료재77～425 K구유량호적온도특성,425 K시적발사강도위77 K적58%좌우.수차장타문화근자외LED(～400 nm)、람광LED(～460 nm)봉장성고량도황록광화황광LED이급백광LED,발광효솔고체19 lm/W,저사봉장적LED적발광성능야수착Eu~(2+)농도,이급분효비례변화이정규률성변화.
A series of Sr_(1-y)Eu_ySi_2O_(2-z)N_(2+2z/3) phosphors were synthesized by the high-temperature solid-state reaction and characterized systematically.The X-ray powder diffraction analysis confirms the formation of a solid solution of Sr_(1-y)Eu_ySi_2O_(2-z)N_(2+2z/3) phosphor for Eu concentration from 0 to 0.2. The photoluminescence properties show that the phosphors can be efficiently excited by UV-visible light from 250 to 500 nm and exhibit intense tunable yellowish green light due to Eu concentration. The relationship among the lowest 5d absorption bands, Stocks shifts, the centroid shifts and splitting of Eu~(2+) levels was studied in details. The temperature dependent emission spectra in the temperature range of 77～450 K show that they have a high thermal quenching temperature above 450 K. The LED based on UV/blue chip and Sr_(1-y)Eu_ySi_2O_(2-z)N_(2+2z/3) phosphors were encapsulated firstly, which show intense green, white and lower UV light emission. Their luminescent properties agree well with these phosphors. The luminous efficiency of the fabricated LED can reach 19 lm/W and the white LED can be obtained from the phosphors fabricated with blue chip based on different gel concentration. These results indicate that Sr_(1-y)Eu_ySi_2O_(2-z)N_(2+2z/3) phosphors are promising candidates for solid-state lighting LED.