Huang Hai, Li Renfu, Jin Shilin, Li Zhifang, Huang Ping, Hong Jinquan, Du Shaowu, Zheng Wei, Chen Xueyuan, Chen Daqin
Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou 350117, China.
CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
ACS Appl Mater Interfaces. 2021 Jul 28;13(29):34561-34571. doi: 10.1021/acsami.1c09421. Epub 2021 Jul 18.
Exploring highly efficient near-infrared (NIR) emitting materials is desirable for the advancement of next-generation smart NIR light sources. Different from most reported Cr-doped emitters with far-red emissions, Yb-activated phosphors are expected to yield pure NIR (∼1000 nm) light. Herein, a new hot-injection route using all metal-oleate salts to fabricate Yb-doped CsPbCl perovskite nanocrystals (PeNCs) is reported for the first time, which produce PeNC-sensitized Yb NIR emission with photoluminescence quantum yields (PLQYs) higher than 100%. With the help of temperature-dependent PL spectra, femtosecond transient absorption spectra, and time-resolved PL spectra, it is evidenced that the in situ produced intrinsic shallow trap states in a CsPbCl host play a key role in facilitating the picosecond nonradiative cooperative energy transfer from PeNCs to two Yb dopants simultaneously. Using the optimized Yb:CsPbCl quantum cutters, a phosphor-converted NIR light-emitting diode (pc-NIR-LED) is fabricated, exhibiting an external quantum efficiency of 2%@28 mA, a high NIR output irradiance of 112 mW/cm@400 mA, and excellent long-term stability. Finally, the designed pc-NIR-LED is demonstrated to have great potential as an invisible night-vision light source.
探索高效近红外（NIR）发光材料对于下一代智能近红外光源的发展至关重要。与大多数报道的具有远红色发射的Cr掺杂发光体不同，Yb激活的磷光体有望产生纯近红外（~1000 nm）光。在此，首次报道了一种使用全金属油酸盐制备Yb掺杂的CsPbCl钙钛矿纳米晶体（PeNCs）的新热注入路线，该路线产生的PeNC敏化Yb近红外发射的光致发光量子产率（PLQYs）高于100%。借助于温度相关的PL光谱、飞秒瞬态吸收光谱和时间分辨PL光谱，证明了CsPbCl主体中原位产生的本征浅陷阱态在促进皮秒级非辐射协同能量从PeNCs同时转移到两个Yb掺杂剂方面起着关键作用。使用优化的Yb:CsPbCl量子切割器，制备了一种磷光体转换近红外发光二极管（pc-NIR-LED），在28 mA时表现出2%的外量子效率，在400 mA时具有112 mW/cm的高近红外输出辐照度，以及出色的长期稳定性。最后，所设计的pc-NIR-LED被证明作为一种不可见夜视光源具有巨大潜力。
