Efficient sky-blue perovskite light-emitting diodes via photoluminescence enhancement
Efficient sky-blue perovskite light-emitting diodes via photoluminescence enhancement
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DOI：
10.1038/s41467-019-13580-w
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发表时间：
2019-12-10
影响因子：
16.6
通讯作者：
Huang, Jinsong
中科院分区：
文献类型：
--
作者：
Wang, Qi;Wang, Xiaoming;Huang, Jinsong
绿色和红色钙钛矿发光二极管（PeLED）的效率已接近其理论上限，而蓝色PeLED的效率则远远落后。在此，我们报告通过克服宽带隙钙钛矿光致发光量子效率低的主要障碍来提高天蓝色 PeLED 的效率。将苯乙基氯化铵混合到铯铅卤化物钙钛矿中，产生二维和三维钙钛矿的混合物，将光致发光量子效率从 1.1% 提高到 19.8%。在混合物中添加氯化钇(III)可进一步将光致发光量子效率提高至49.7%。钇被发现融入三维钙钛矿晶粒中，同时它仍然富含在晶界和表面。晶粒表面的钇增加了晶粒壳的带隙，从而将电荷载流子限制在晶粒内部以实现有效的辐射复合。天蓝色和蓝色 PeLED 分别获得了 11.0% 和 4.8% 的创纪录效率。
The efficiencies of green and red perovskite light-emitting diodes (PeLEDs) have been increased close to their theoretical upper limit, while the efficiency of blue PeLEDs is lagging far behind. Here we report enhancing the efficiency of sky-blue PeLEDs by overcoming a major hurdle of low photoluminescence quantum efficiency in wide-bandgap perovskites. Blending phenylethylammonium chloride into cesium lead halide perovskites yields a mixture of two-dimensional and three-dimensional perovskites, which enhances photoluminescence quantum efficiency from 1.1% to 19.8%. Adding yttrium (III) chloride into the mixture further enhances photoluminescence quantum efficiency to 49.7%. Yttrium is found to incorporate into the three-dimensional perovskite grain, while it is still rich at grain boundaries and surfaces. The yttrium on grain surface increases the bandgap of grain shell, which confines the charge carriers inside grains for efficient radiative recombination. Record efficiencies of 11.0% and 4.8% were obtained in sky-blue and blue PeLEDs, respectively.