Despite heavy research, blue perovskite nanocrystal LEDs have struggled to match the high efficiencies of their red and green cousins, particularly at wavelengths blue enough to meet the NTSC blue standard. One of the most critical problems is the low photoluminescence yield of the nanocrystals in thin films. Recently, manganese doping has been shown to increase the photoluminescence yield of the perovskite even as a decay pathway to a long-lived emissive state on the manganese ion is introduced. Here, we employ a two-step synthetic approach to carefully tune the manganese doping to increase the blue photoluminescence while preventing significant manganese emission, allowing for blue perovskite LEDs with quantum efficiencies over 2% that meet the NTSC standard. Manganese doping increases the photoluminescence yield and lifetime, reduces trap states, and makes the dots more monodisperse, reducing the emission bandwidth. Finally, we utilize perovskite nanocrystal downconverters to build an all-perovskite white LED.

尽管进行了大量研究，但蓝色钙钛矿纳米晶体LED仍在努力匹配其红色和绿色表亲的高效率，特别是在蓝色波长足以满足NTSC蓝色标准的情况下。最关键的问题之一是薄膜中纳米晶体的低光致发光产率。近来，已显示出锰掺杂增加了钙钛矿的光致发光产量，即使引入了向锰离子上长寿命发射态的衰变途径。在这里，我们采用两步合成方法来仔细调整锰掺杂量，以增加蓝色光致发光，同时防止大量锰排放，从而使量子效率超过2％的蓝色钙钛矿LED达到NTSC标准。锰掺杂增加了光致发光的产量和寿命，减少了陷阱状态，并使点更单分散，从而减小了发射带宽。最后，我们利用钙钛矿纳米晶体下变频器来构建全钙钛矿白光LED。