College of Physics and Energy, Fujian Normal University, Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, Fuzhou, Fujian, 350117, China.
CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials and State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
Mater Horiz. 2023 Apr 3;10(4):1406-1415. doi: 10.1039/d2mh01396g.
Nonlinear multi-phonon (2-7) absorption in the Na/Bi-alloyed CsAgInCl lead-free double perovskites with ∼100% photoluminescence quantum yield and superior stability is observed for the first time, which can be pumped by a femtosecond laser in a wide spectral range (800-2600 nm). First-principles calculations verify that the parity-forbidden transition from the valence band maximum and conduction band minimum (at the point) is not broken by Na/Bi doping, and strong optical band-to-band absorption occurs at the & points. Time-resolved emission spectra evidence that single-photon and multi-photon pumping leads to the same self-trapped exciton transition and high-order nonlinear absorption will not induce a remarkable thermal effect. Finally, we demonstrate that the CsNaAgInBiCl DP shows great potential for next-generation wavelength-selective and highly sensitive multiphoton imaging applications.
首次观察到具有约 100%光致发光量子产率和优异稳定性的 Na/Bi 共掺 CsAgInCl 无铅双钙钛矿中的非线性多声子（2-7）吸收，该吸收可在较宽的光谱范围（800-2600nm）内通过飞秒激光进行激发。第一性原理计算验证了价带顶和导带底（在 Γ 点）之间的宇称禁戒跃迁不会被 Na/Bi 掺杂破坏，并且在 Γ 点处会发生强烈的光带带吸收。时间分辨发射光谱表明，单光子和多光子激发会导致相同的自陷激子跃迁，并且高阶非线性吸收不会引起明显的热效应。最后，我们证明 CsNaAgInBiCl DP 在下一代波长选择性和高灵敏度多光子成像应用中具有巨大的潜力。
