4⁃氟苯乙胺基准二维钙钛矿的合成及其电致发光与激光性能

4⁃Fluorophenylethylamine⁃based novel quasi⁃two⁃dimensional perovskites:synthesis,electroluminescence,and laser properties

设计并开发了一种兼具电致发光和光学增益性能的准二维钙钛矿材料。通过向三维钙钛矿CsPbBr3中引入大体积阳离子4-FPEA+(4-氟苯乙胺),利用简易的溶液旋涂法,制备了不同n值量子阱混合分布的准二维钙钛矿薄膜。通过紫外可见吸收光谱和光致发光光谱证明调整4-FPEA+的添加量可以对量子阱的分布进行有效调控。结合扫描电子显微镜和原子力显微镜证明4-FPEA+的加入可以降低薄膜表面粗糙度。当4-FPEA+和CsPbBr3的物质的量之比为0.6时,薄膜的发光强度最高。将该材料应用在发光二极管(light emitting diodes,LEDs)中,结合冠醚作为添加剂辅助钝化缺陷,实现了外量子效率(EQE)为0.98%的绿光LED器件。在激光性能方面,该材料在室温条件下的最低阈值为17.42μJ·cm^(-2),增益系数为35 cm^(-1)。

A series of quasi-2D perovskites with both electroluminescence and optical gain properties were designed and synthesized in this work.The 4-FPEA+(4-FPEAB=4-fluorophenylethylamine hydrobromide)was introduced into CsPbBr3 to prepared quasi-2D perovskites thin films with different n-value quantum wells distribution by using simple solution coating method.The UV-Vis absorption and photoluminescence spectra were adopted to suggest that quantum wells distribution can be modulated effectively by controlling the proportion of precursors in solution precisely.These samples were characterized by scanning electron microscopy and atomic force microscopy.The result suggested that 4-FPEA+can reduce surface roughness efficiently.When the molar ratio of 4-FPEA+and CsPbBr3 reached 0.6,as-prepared perovskite films were demonstrated with the highest brightness.Using additive defect passivation strategy with crown ether,more uniform quantum well distribution achieved which further promoted the efficient energy transfer.The light emitting diodes(LED)devices realized the external quantum efficiencies(EQE)as 0.98%.In terms of laser performance,amplified spontaneous emissions(ASEs)with a low threshold of 17.42μJ·cm^(-2) and gain coefficients as 35 cm^(-1) in room temperature were realized.