Ce/Tb/Mn共激活单基质白光发射稀土无铅双钙钛矿与白光LED器件

Ce/Tb/Mn Co-activated Single Matrix White Light Emitting Rare Earth Lead-Free Double Perovskite and Its Potential Application in Warm White LED

金属铅卤钙钛矿由于其优异的光电性能已经广泛应用于各种光电器件当中,包括太阳能电池、发光二极管器件(LED)、光电检测器等,然而铅基钙钛矿的毒性和差的稳定性仍是当前相关研究的巨大挑战。通过水热法成功合成了一种低毒性和高效的无铅稀土双钙钛矿,通过三基色发光中心Ce/Tb/Mn的能量传递调控,获得了一种稀土双钙钛矿单基质白光发射材料Cs2NaCexTb1-xCl6:xMn^2+,系统研究了其晶体结构、激发、发射光谱和能量传递机制与效率。研究结果表明:Cs2NaCe0.2Tb0.8Cl6:1%Mn^2+在紫外区域表现出强而较宽的吸收,呈现较强的暖白光发射,其量子效率为67.25%。此外,该材料在UV-LED (365 nm, 150 mW·cm^-2)照射60 min后,样品的发光强度降低仅仅为5%;在100和200℃下热处理30 min后,样品的发光强度降低仅仅为5%和14%;结合商用365 nm LED芯片,得到了理想的暖白光LED,其色坐标为(x=0.41,y=0.46),色温为3849 K。上述结果提出了一种高效单基质镧系全无机双钙钛矿用于白色发光二极管(WLEDs)的潜在方法。

Metal lead halide perovskites have been widely used in various optoelectronic devices due to their excellent photoelectric properties, including solar cells, light emitting diode devices(LED), photodetectors, etc. However, the toxicity and poor stability of lead-based perovskites are still huge challenges in related research. In this paper, a lead-free rare earth double perovskite with low toxicity and high-efficiency was successfully synthesized by hydrothermal method. By co-doping Ce/Tb/Mn, a rare earth double perovskite single matrix white light emitting material Cs2NaCexTb1-xCl6:xMn^2+ is synthesized. The crystal structure, excitation, emission spectrum, and energy transfer mechanism and efficiency have been systematically studied. The results show that Cs2NaCe0.2Tb0.8Cl6:1% Mn^2+ shows strong and wide absorption in the ultraviolet region and exhibits intense warm white light emission with quantum efficiency of 67.25%. In addition, after UV-LED(365 nm, 150 mW·cm^-2) irradiation for 60 min, the luminous intensity of the sample was reduced by only 5%;After heat-treatment at 100 and 200 ℃ for 30 min, the luminous intensity of the sample was reduced by only 5% and 14%.Combined with a commercial 365 nm LED chip, an ideal warm white LED with a color coordinate of(x=0.41, y=0.46) and a color temperature of 3849 K were successfully fabricated. The above results suggest lanthanide all-inorganic double perovskites are potentially promising as an efficient single-matrix for white light emitting diodes(WLEDs).