Jung Mi-Hee
Department of Nanotechnology and Advanced Materials Engineering , Sejong University , 209, Neungdong-ro , Gwangjin-gu, Seoul 05006 , Republic of Korea.
Inorg Chem. 2019 May 20;58(10):6748-6757. doi: 10.1021/acs.inorgchem.9b00145. Epub 2019 May 1.
Two-dimensional (2D) perovskites, which have a 2D orientation of the inorganic framework that determines largely the electronic characteristics and an organic cation in the interlayer that leads to a quantum well structure, have attracted a great deal of attention due to their superior stable optoelectronic properties. Especially, some of the greatest interest in 2D perovskites is their application in broad-band white-light emission for solid state lighting. We prepared (BZA)PbBrCl (BZA= benzylammonium and x = 0, 1.5, 2, 3, 3.5, 4) to tune the white-light emission. In the (BZA)PbBr perovskite structure, the bond lengths of Pb-Br for PbBr exhibit the same lengths of 2.98 and 3.00 Å, respectively. However, in PbCl octahedra the bridging Pb-Cl distances were 2.83/2.88 Å and 2.85/2.88 Å, respectively. The 2D perovskite (BZA)PbCl exhibits a turquoise light emission due to its highly distorted structure, whereas (BZA)PbBr emits a narrow blue emission. We controlled the white emission by mixing the two compounds in proportion and changed the color from blue to white using the intermediate compound (BZA)PbBrCl ( x = 1.5, 2, 3, 3.5). The intermediate compound (BZA)PbBrCl ( x = 1.5, 2, 3, 3.5) shifted in the white space of Commission Internationale de l'Éclairage coordinates, which were (0.324, 0.383), (0.312. 0.369), (0.319, 0.374), and (0.338, 0.396), respectively. The correlated color temperature of all compounds was observed above 5000 K, which suggests that these perovskites could be utilized as "cold" white-light-emitting materials.
二维（2D）钙钛矿具有无机骨架的二维取向，这在很大程度上决定了其电子特性，并且层间含有有机阳离子，形成量子阱结构，因其优异的稳定光电性能而备受关注。特别是，二维钙钛矿最受关注的应用之一是其在固态照明的宽带白光发射中的应用。我们制备了（BZA）PbBrCl（BZA = 苄基铵，x = 0、1.5、2、3、3.5、4）以调节白光发射。在（BZA）PbBr钙钛矿结构中，PbBr的Pb - Br键长分别显示为相同的2.98 Å和3.00 Å。然而，在PbCl八面体中，桥连的Pb - Cl距离分别为2.83/2.88 Å和2.85/2.88 Å。二维钙钛矿（BZA）PbCl由于其高度扭曲的结构而呈现绿松石色发光，而（BZA）PbBr发出窄蓝光。我们通过按比例混合这两种化合物来控制白色发射，并使用中间化合物（BZA）PbBrCl（x = 1.5、2、3、3.5）将颜色从蓝色变为白色。中间化合物（BZA）PbBrCl（x = 1.5、2、3、3.5）在国际照明委员会坐标的白色空间中移动，分别为（0.324，0.383）、（0.312，0.369）、（0.319，0.374）和（0.338，0.396）。观察到所有化合物的相关色温均高于5000 K，这表明这些钙钛矿可用作“冷”白光发射材料。
