Lang Arad, Chen Celia, Ye Chumei, McHugh Lauren N, Chua Xian Wei, Stranks Samuel D, Dutton Siân E, Bennett Thomas D
Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, U.K.
Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
J Am Chem Soc. 2024 Dec 11;146(49):33945-33955. doi: 10.1021/jacs.4c12697. Epub 2024 Nov 21.
Melt alloying, the process of melting a physical powder blend to create a homogeneous alloy, is widely used in materials processing. By carefully selecting the materials and their proportions, the physical properties of the resulting alloy can be precisely controlled. In this study, we investigate the possibility of utilizing melt alloying principles for meltable two-dimensional hybrid organic-inorganic perovskites (2D-HOIPs). We blend and melt mixtures of two selected 2D-HOIPs: the glass-forming (-NEA)PbBr (-NEA = ()-(-)-1-(1-naphthyl)ethylammonium) and the liquid-forming (1-MHA)PbI (1-MHA = 1-methylhexylammonium). Upon melting and cooling, 1-MHA-poor blends ( ≤ 50% mol, where corresponds to the relative molar concentration of (1-MHA)PbI in the blend) form a hybrid glass, while 1-MHA-rich blends ( ≥ 70% mol) crystallize. The melting temperature of all blends, as well as the glass transition temperature of the glass-forming blends, change according to blend composition. In all cases, melting produces a homogeneous structure, either glassy or crystalline, which remains such after the glassy samples are recrystallized upon a second heat treatment. This method enables band gap tuning of the blends, given that it varies with composition and crystallinity. Overall, this work demonstrates the applicability of classical melt processing to binary-component functional hybrid systems, and paves the way to solvent-free perovskite-based device fabrication.
熔融合金化是将物理粉末混合物熔化以形成均质合金的过程，在材料加工中被广泛应用。通过仔细选择材料及其比例，可以精确控制所得合金的物理性能。在本研究中，我们探究了将熔融合金化原理应用于可熔融二维有机-无机杂化钙钛矿（2D-HOIPs）的可能性。我们将两种选定的2D-HOIPs混合并熔化：形成玻璃态的（-NEA）PbBr（-NEA =（）-（-）-1-（1-萘基）乙铵）和形成液态的（1-MHA）PbI（1-MHA = 1-甲基己基铵）。熔化并冷却后，贫1-MHA的混合物（≤50%摩尔，其中对应于混合物中（1-MHA）PbI的相对摩尔浓度）形成杂化玻璃，而富1-MHA的混合物（≥70%摩尔）结晶。所有混合物的熔化温度以及形成玻璃态混合物的玻璃化转变温度均随混合物组成而变化。在所有情况下，熔化都会产生均质结构，无论是玻璃态还是晶态，在对玻璃态样品进行二次热处理使其重结晶后仍保持这种结构。鉴于带隙随组成和结晶度而变化，该方法能够对混合物的带隙进行调节。总体而言，这项工作证明了经典熔融加工对二元组分功能杂化体系的适用性，并为无溶剂钙钛矿基器件制造铺平了道路。
