Details

Autor(en) / Beteiligte

• Liu, Youyu
• Xie, Zhi
• Zheng, Wei
• Huang, Ping
• Gong, Zhongliang
• Zhang, Wei
• Shao, Zhiqing
• Yang, Dengfeng
• Chen, Xueyuan

Titel

High-efficiency narrow-band blue emission from lead-doped Cs2ZnBr4 nanocrystals

Ist Teil von

• Chemical engineering journal (Lausanne, Switzerland : 1996), 2023-03, Vol.460, p.141683, Article 141683

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• [Display omitted] •Minor Pb2+ ions (<0.1 mol%) can substitute the tetrahedral Zn2+ site in Cs2ZnBr4 NCs.•Cs2ZnBr4: Pb2+ NCs exhibit narrow-band blue PL with a QY of 82.9 % and a FWHM of 10.2 nm.•The PL of Cs2ZnBr4: Pb2+ NCs stems from the Pb2+ impurity-induced trapped exciton emission.•Dual-band-tunable blue/green PL is achieved in Cs2ZnBr4: Pb2+/CsPbBr3 hybrid NCs.•Cs2ZnBr4: Pb2+/CsPbBr3 hybrid NCs display much better stability than bare CsPbBr3. All-inorganic metal halide nanocrystals (NCs) with high-efficiency narrow-band photoluminescence (PL) are highly desirable for display applications. Herein, we report a strategy to achieve efficient narrow-band blue PL in 0D Cs2ZnBr4 NCs via minor Pb2+ doping. Upon doping with 0.1 mol% Pb2+, the intrinsically non-luminescent Cs2ZnBr4 NCs become efficiently luminescent, with a sharp emission peak at 433 nm (full-width at half maximum of ≈10.2 nm) and a high quantum yield of 82.9 %. With the aid of the first-principles calculations, we unveil that the narrow-band blue PL originates from the localized exciton emission arising from the peculiar electronic band structure induced by Pb2+ doping, in which the photogenerated excitons in [PbBr4]2− tetrahedra are trapped and localized within [ZnBr4]2− tetrahedra. Furthermore, by control of the Pb2+ concentration (0.1–3.0 mol%), we achieve dual-band-tunable blue/green PL in Cs2ZnBr4: Pb2+/CsPbBr3 hybrid NCs with high efficiency and signifcantly improved stability compared to that of bare CsPbBr3. These findings provide a unique approach to achieve highly efficient narrow-band PL in metal halide NCs via minor Pb2+ doping, which largely mitigates the toxicity concern about lead halide perovskites and thus may open up new opportunities for the materials design and device engineering in practical applications.