Prochowicz Daniel, Saski Marcin, Yadav Pankaj, Grätzel Michael, Lewiński Janusz
Institute of Physical Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland.
Department of Solar Energy, School of Technology , Pandit Deendayal Petroleum University , Gandhinagar , 382 007 Gujarat , India.
Acc Chem Res. 2019 Nov 19;52(11):3233-3243. doi: 10.1021/acs.accounts.9b00454. Epub 2019 Nov 8.
Hybrid organic-inorganic metal halide perovskites (MHPs) have emerged as excellent absorber materials for next generation solar cells owing to their simple solution-processed synthesis and high efficiency. This breakthrough in photovoltaics along with an accompanying impact in light-emitting applications prompted a renaissance of interest in the broad family of MHPs. Notably, the optoelectronic properties and the photovoltaic parameters of MHPs are highly sensitive to the adopted synthetic strategy. The preparation of MHPs has commonly relied on solution-based methods requiring elevated temperatures for homogeneity of reaction mixtures. While the solution-based approach is relatively versatile, it faces challenges such as limitations in compositional engineering of MHPs or their long-term storage among others. Therefore, there is a continuous great challenge to develop efficient synthetic strategies affording various high-quality MHP materials for numerous technological optoelectronic applications. In the past decade, mechanochemistry has appeared as a green alternative to traditional synthesis. This solid-state, re-emerging efficient synthetic methodology mediated by direct absorption of mechanical energy is growing explosively across organic and inorganic chemistry and materials science. In this Account, we describe our shared interest in the productive use of mechanical force in chemistry of MHPs, as well as assembly of the respective solar cell devices. We highlight the milestones achieved by our groups along with the seminal contributions by other groups. In particular, we demonstrate that mechanochemistry efficiently allows the formation of various phase pure hybrid lead and lead-free halide perovskite compositions (called hereafter "mechanoperovskites"). The progress in solvent-free solid-state synthesis is greatly enhanced by the integration of advanced methods of solid-state analysis like powder X-ray diffraction (pXRD), solid-state nuclear magnetic resonance (ss-NMR) and UV-vis spectroscopies, and we aim to illustrate this ongoing integration through appropriate examples. Furthermore, we show that thin films based on mechanoperovskites have the advantage of providing a higher degree of control of the stoichiometry and higher reproducibility, stability, and material phase purity. The impact of using powdered mechanoperovskite as a precursor for thin film formation on the electrochemical and photovoltaic properties of the solar cells is also discussed. Finally, our view of current challenges and future directions in this emerging interdisciplinary area of research is provided.
有机-无机杂化金属卤化物钙钛矿（MHPs）因其简单的溶液法合成和高效率，已成为下一代太阳能电池的优异吸收材料。光伏领域的这一突破以及在发光应用中的伴随影响，引发了人们对MHPs大家族兴趣的复兴。值得注意的是，MHPs的光电性质和光伏参数对所采用的合成策略高度敏感。MHPs的制备通常依赖于基于溶液的方法，这种方法需要升高温度以实现反应混合物的均匀性。虽然基于溶液的方法相对通用，但它面临着诸如MHPs组成工程的局限性或其长期储存等挑战。因此，开发高效的合成策略以提供用于众多技术光电应用的各种高质量MHP材料一直是一个巨大的挑战。在过去十年中，机械化学作为传统合成的绿色替代方法出现。这种由机械能直接吸收介导的固态、重新出现的高效合成方法正在有机和无机化学以及材料科学领域迅速发展。在本综述中，我们描述了我们对在MHPs化学中有效利用机械力以及相应太阳能电池器件组装的共同兴趣。我们突出了我们团队取得的里程碑以及其他团队的开创性贡献。特别是，我们证明机械化学能够有效地形成各种相纯的杂化铅基和无铅卤化物钙钛矿组合物（以下称为“机械钙钛矿”）。通过整合粉末X射线衍射（pXRD）、固态核磁共振（ss-NMR）和紫外可见光谱等先进的固态分析方法，无溶剂固态合成取得了很大进展，我们旨在通过适当的例子来说明这种持续的整合。此外，我们表明基于机械钙钛矿的薄膜具有在化学计量控制、更高的重现性、稳定性和材料相纯度方面提供更高程度控制的优势。还讨论了使用粉末状机械钙钛矿作为薄膜形成前体对太阳能电池的电化学和光伏性质的影响。最后，我们提供了对这个新兴跨学科研究领域当前挑战和未来方向的看法。
