Protesescu Loredana, Yakunin Sergii, Bodnarchuk Maryna I, Krieg Franziska, Caputo Riccarda, Hendon Christopher H, Yang Ruo Xi, Walsh Aron, Kovalenko Maksym V
†Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland.
‡Laboratory for Thin Films and Photovoltaics, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
Nano Lett. 2015 Jun 10;15(6):3692-6. doi: 10.1021/nl5048779. Epub 2015 Feb 2.
Metal halides perovskites, such as hybrid organic-inorganic CH3NH3PbI3, are newcomer optoelectronic materials that have attracted enormous attention as solution-deposited absorbing layers in solar cells with power conversion efficiencies reaching 20%. Herein we demonstrate a new avenue for halide perovskites by designing highly luminescent perovskite-based colloidal quantum dot materials. We have synthesized monodisperse colloidal nanocubes (4-15 nm edge lengths) of fully inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I or mixed halide systems Cl/Br and Br/I) using inexpensive commercial precursors. Through compositional modulations and quantum size-effects, the bandgap energies and emission spectra are readily tunable over the entire visible spectral region of 410-700 nm. The photoluminescence of CsPbX3 nanocrystals is characterized by narrow emission line-widths of 12-42 nm, wide color gamut covering up to 140% of the NTSC color standard, high quantum yields of up to 90%, and radiative lifetimes in the range of 1-29 ns. The compelling combination of enhanced optical properties and chemical robustness makes CsPbX3 nanocrystals appealing for optoelectronic applications, particularly for blue and green spectral regions (410-530 nm), where typical metal chalcogenide-based quantum dots suffer from photodegradation.
金属卤化物钙钛矿，如有机-无机杂化的CH3NH3PbI3，是新型的光电子材料，作为太阳能电池中的溶液沉积吸收层已引起了广泛关注，其功率转换效率可达20%。在此，我们通过设计高发光性的钙钛矿基胶体量子点材料，展示了卤化物钙钛矿的一条新途径。我们使用廉价的商业前驱体合成了完全无机的卤化铯铅钙钛矿（CsPbX3，X = Cl、Br和I或混合卤化物体系Cl/Br和Br/I）的单分散胶体纳米立方体（边长4-15纳米）。通过成分调制和量子尺寸效应，带隙能量和发射光谱在410-700纳米的整个可见光谱区域内易于调节。CsPbX3纳米晶体的光致发光具有以下特点：发射线宽窄，为12-42纳米；色域宽，覆盖高达NTSC颜色标准的140%；量子产率高，可达90%；辐射寿命在1-29纳秒范围内。增强的光学性能和化学稳定性的有力结合，使得CsPbX3纳米晶体在光电子应用中具有吸引力，特别是对于蓝色和绿色光谱区域（410-530纳米），在该区域典型的金属硫族化物基量子点会发生光降解。
