Hu Qingsong, Niu Guangda, Zheng Zhi, Li Shunran, Zhang Yanan, Song Haisheng, Zhai Tianyou, Tang Jiang
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
Shenzhen R&D Center of Huazhong University of Science and Technology, Guangdong, Shenzhen, 518000, China.
Small. 2019 Oct;15(44):e1903496. doi: 10.1002/smll.201903496. Epub 2019 Sep 5.
Recently, Bi-doped Cs Ag Na InCl lead-free double perovskites demonstrating efficient warm-white emission have been reported. To enable the solution processing and enrich the application fields of this promising material, here a colloidal synthesis of Cs Ag Na In Bi Cl nanocrystals is further developed. Different from its bulk states, the emission color temperatures of the nanocrystal can be tuned from 9759.7 to 4429.2 K by Na and Bi incorporation. Furthermore, the newly developed nanocrystals can break the wavefunction symmetry of the self-trapped excitons by partial replacement of Ag ions with Na ions and consequently allow radiative recombination. Assisted with Bi ions doping and ligand passivation, the photoluminescence quantum yield of the Cs Ag Na In Bi Cl nanocrystals is further promoted to 64%, which is the highest value for lead-free perovskite nanocrystals at present. The new colloidal nanocrystals with tunable color temperature and efficient photoluminescence are expected to greatly advance the research progress of lead-free perovskites in single-emitter-based white emitting materials and devices.
最近，有报道称双掺杂铯银钠铟氯无铅双钙钛矿具有高效的暖白色发射。为了实现溶液加工并拓展这种有前景材料的应用领域，本文进一步开发了一种用于合成铯银钠铟铋氯纳米晶体的胶体合成方法。与体相状态不同，通过掺入钠和铋，纳米晶体的发射色温可在9759.7至4429.2 K之间调节。此外，新开发的纳米晶体可以通过用钠离子部分取代银离子来打破自陷激子的波函数对称性，从而实现辐射复合。在铋离子掺杂和配体钝化的辅助下，铯银钠铟铋氯纳米晶体的光致发光量子产率进一步提高到64%，这是目前无铅钙钛矿纳米晶体的最高值。这种具有可调色温且光致发光效率高的新型胶体纳米晶体有望极大地推动无铅钙钛矿在基于单发射体的白色发光材料和器件方面的研究进展。
