Pradeepkumar Maurya Sandeep, Kathirvel Aruchamy, Ghosh Sayan, Sudakar Chandran
Multifunctional Materials Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
Sci Rep. 2025 Jan 4;15(1):843. doi: 10.1038/s41598-025-85326-2.
The utilization of single crystals is exponentially growing in optoelectronic devices due to their exceptional benefits, including high phase purity and the absence of grain boundaries. However, achieving single crystals with a porous structure poses significant challenges. In this study, we present a method for fabricating porous single crystals (porous-SC) of CsAgBiBr and related halide double perovskites using an infrared-assisted spin coating technique. The porous-SC are formed through a non-classical crystallization process, where oriented crystallographic platelets assemble into porous-SC clusters and merge to create iso-oriented single crystalline building blocks, with pore regions primarily located in the gaps between the platelets. Large porous square-shaped CsAgBiBr halide double perovskite (HDP) single crystals with lateral dimension ~ 10 to 50 μm and few µm thickness are realized with preferred orientation along {h00} on the FTO substrate upon subsequent spin-coating of layers. Analysis using angle-resolved polarized Raman spectroscopy, X-ray diffraction and transmission electron microscopy confirms the formation of single crystals of CsAgBiBr. Further, to get a uniform coating of highly interconnected porous-SC clusters, wiping method under IR illumination is employed. Solar cell devices fabricated from these porous-SCs perform better with J =1.40 mA/cm, V=1.04 V and η = 0.86% than the conventional polycrystalline thin films with J = 0.55 mA/cm, V=0.94 V and η = 0.28%. CsAgBiBr porous-SC shows potential for a wide range of optoelectronic and photoelectrochemical applications.
由于单晶具有诸如高相纯度和无晶界等卓越优势，其在光电器件中的应用正在呈指数级增长。然而，制备具有多孔结构的单晶面临着重大挑战。在本研究中，我们展示了一种使用红外辅助旋涂技术制备CsAgBiBr及相关卤化物双钙钛矿多孔单晶（porous-SC）的方法。多孔-SC是通过非经典结晶过程形成的，在该过程中，取向的晶体片层组装成多孔-SC簇并合并形成等取向的单晶结构单元，孔隙区域主要位于片层之间的间隙中。在FTO基板上随后旋涂各层时，可实现横向尺寸约为10至50μm且厚度为几μm的大型多孔方形CsAgBiBr卤化物双钙钛矿（HDP）单晶，并沿{h00}方向具有择优取向。使用角分辨偏振拉曼光谱、X射线衍射和透射电子显微镜进行的分析证实了CsAgBiBr单晶的形成。此外，为了获得高度互连的多孔-SC簇的均匀涂层，采用了红外光照下的擦拭方法。由这些多孔-SC制成的太阳能电池器件表现更佳，其J = 1.40 mA/cm²，V = 1.04 V，η = 0.86%，优于传统多晶薄膜，后者的J = 0.55 mA/cm²，V = 0.94 V，η = 0.28%。CsAgBiBr多孔-SC在广泛的光电子和光电化学应用中显示出潜力。
