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1. Piezoelectricity in chalcogenide perovskites

   https://doi.org/10.1038/s41467-024-50130-5  

   Abir, Sk_Shamim_Hasan; Sharma, Shyam; Sharma, Prince; Karla, Surya; Balasubramanian, Ganesh; Samuel, Johnson; Koratkar, Nikhil (July 2024, Nature Communications)

   Abstract Piezoelectric materials show potential to harvest the ubiquitous, abundant, and renewable energy associated with mechanical vibrations. However, the best performing piezoelectric materials typically contain lead which is a carcinogen. Such lead-containing materials are hazardous and are being increasingly curtailed by environmental regulations. In this study, we report that the lead-free chalcogenide perovskite family of materials exhibits piezoelectricity. First-principles calculations indicate that even though these materials are centrosymmetric, they are readily polarizable when deformed. The reason for this is shown to be a loosely packed unit cell, containing a significant volume of vacant space. This allows for an extended displacement of the ions, enabling symmetry reduction, and resulting in an enhanced displacement-mediated dipole moment. Piezoresponse force microscopy performed on BaZrS₃confirmed that the material is piezoelectric. Composites of BaZrS₃particles dispersed in polycaprolactone were developed to harvest energy from human body motion for the purposes of powering electrochemical and electronic devices. 

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2. Mixed-valence halide perovskites

   https://doi.org/10.1016/j.ccr.2025.216719  

   Deschene, Christina R; Zwanziger, Clara; Matheu, Roc; Karunadasa, Hemamala I (September 2025, Coordination Chemistry Reviews)
3. Polymorphism in metal halide perovskites

   https://doi.org/10.1039/D0MA00643B  

   Alaei, Aida; Circelli, Abigail; Yuan, Yihang; Yang, Yi; Lee, Stephanie S. (January 2021, Materials Advances)

   null (Ed.)

   Metal halide perovskites (MHPs) are frontrunners among solution-processable materials for lightweight, large-area and flexible optoelectronics. These materials, with the general chemical formula AMX 3 , are structurally complex, undergoing multiple polymorph transitions as a function of temperature and pressure. In this review, we provide a detailed overview of polymorphism in three-dimensional MHPs as a function of composition, with A = Cs + , MA + , or FA + , M = Pb 2+ or Sn 2+ , and X = Cl − , Br − , or I − . In general, perovskites adopt a highly symmetric cubic structure at elevated temperatures. With decreasing temperatures, the corner-sharing MX 6 octahedra tilt with respect to one another, resulting in multiple polymorph transitions to lower-symmetry tetragonal and orthorhombic structures. The temperatures at which these phase transitions occur can be tuned via different strategies, including crystal size reduction, confinement in scaffolds and (de-)pressurization. As discussed in the final section of this review, these solid-state phase transformations can significantly affect optoelectronic properties. Understanding factors governing these transitions is thus critical to the development of high-performance, stable devices. 

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4. Laser printed metal halide perovskites

   https://doi.org/10.1088/2515-7639/ab9aac  

   Tyznik, Colin; Lamport, Zachary A.; Sorli, Jeni; Becker-Koch, David; Vaynzof, Yana; Loo, Yueh-Lin; Jurchescu, Oana D. (June 2020, Journal of Physics: Materials)

   Abstract Hybrid organic–inorganic perovskites enable the production of semiconductor devices at low cost from solution processing. Their remarkable structural versatility offers unique and diverse physical properties, leading to their incorporation in a wide variety of applications. One major limitation is the significant negative environmental impact associated with developing perovskite devices; common solvents used in perovskite film deposition are highly toxic, which represents a barrier to the transfer to an industrial setting of the perovskite technology. Here we report on the fabrication and characterisation of the first laser printed organic–inorganic perovskite films. The method is solvent-free, scalable and low-cost, allowing fast deposition over large areas and with minimal material waste. We show that the laser printed perovskite films are crystalline and exhibit electrical properties on par with single crystals, despite the fact that the microstructure consists of randomly oriented crystallites. The toner used during printing is designed for optimal film transfer and the vertical separation of its components results in a segregation of the perovskite film in the middle of the stack, therefore also encapsulating the perovskite layer, a process that yields a remarkable resilience to defect formation upon environmental exposure. 

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5. Low-Dimensional Organometal Halide Perovskites

   https://doi.org/10.1021/acsenergylett.7b00926  

   Lin, Haoran; Zhou, Chenkun; Tian, Yu; Siegrist, Theo; Ma, Biwu (November 2017, ACS Energy Letters)