Inorganic cesium lead halide CsPbI x Br3–x (x = 0–3) perovskites have recently gained considerable attention as semiconductor materials for the fabrication of photodetectors due to their high thermal and environmental stability. However, preparing high-quality CsPbI x Br3–x perovskite films using a simple spin-coating method is challenging. This study focused on enhancing the performance of a solution-processed all-inorganic CsPbI x Br3–x (x = 1, CsPbIBr2) photodetector using a silver iodide (AgI) additive. Introducing a small amount of AgI into the CsPbIBr2 precursor solution resulted in perovskite films that were more uniform and exhibited compact surface morphology that improved crystallinity and electronic properties. To further explore the influence of the AgI-modified CsPbIBr2 perovskite film on the device performance, we fabricated a self-powered photodetector with the geometry of fluorine-doped tin oxide (FTO)/compact TiO2/CsI­(PbBr2)0.99(AgI)0.01/2,2′,7,7′-tetrakis­[N,N-di­(4-methoxyphenyl)­amino]-9,9′-spirobifluorene (Spiro-OMeTAD)/Au. Photoresponse analysis revealed that the photoresponsivity, on/off ratio, and response time of the CsI­(PbBr2)0.99(AgI)0.01 perovskite photodetector were improved. Notably, the CsI­(PbBr2)0.99(AgI)0.01 perovskite device showed a higher responsivity and an impressive detectivity of 0.43 A/W and 2.46 × 1011 Jones, respectively, in comparison to the pristine CsPbIBr2 device. This work demonstrates the excellent potential of using inorganic CsI­(PbBr2)0.99(AgI)0.01 perovskites in applications for high-performance photodetectors.

UV region with the best results showing 0.9 A W −1 responsivity and 0.28/5.3 s rise/decay time. When following a vertical device structure with multiple layers this complexity adds to both fabrication cost and difficulty. [5a,6] We herein report the development of a carbon-based flexible wire-shaped perovskite photodetector. This flexible wire-shaped device performs exceedingly well under low light environments (11 A W −1 ) and is easily woven into composites due to its flexibility and small diameter (≈400 µm). Using a novel in-house fabrication method, we have developed a rapid, repeatable, and scalable annealing process to move closer toward the potential of multifunctional composite materials and embedded wire-shaped photodetectors. The photodetector's small size is critical given that any addition to a composite part cannot have a negative impact on its mechanical properties. There has been reported success with integrated wires in composites for structural health monitoring. [7] As these systems use light emissions at 585 and 617 nm, we have characterized our device under the same conditions.Given the large drop in performance for wire-shaped devices when compared to equivalent structures on planar substrates, fabrication techniques were targeted as a point of improvement; noting that there is no standard method for wire-shaped devices. [8] For comparison, doctor-blade, [9] spray, [10] and spincoating [11] are all well documented and established fabrication methods for perovskite planar devices. However, wire-shaped cell fabrication exhibits less developed solutions [8a,12] and does not benefit from the history of extensive research found for planar thin film cells. It has been shown that methyl ammonium lead iodide perovskite (MAPbI 3 ) necessitates alternative processing such as two-step deposition or solvent engineering methods to create a pinhole-free, continuous thin film adding additional complexity in the fabrication process. [13] However, using MAPbI 3 we have created a continuous thin film on a wire using the joule heating method that shows comparable electrical characteristics to planar rigid perovskite photodetectors.We have developed a first flexible wire-shaped perovskite photodetector using joule heating method for annealing perovskite on CNY that is repeatable, cost effective, and scalable. This method utilizes joule heating in order to uniformly control the temperature of the wire substrate. We believe we have presented a novel solution able to compete with planar device. To the best of our knowledge, no other publication on a wire-shaped perovskite photodetector on thread-like CNY has Organolead triiodide perovskite (CH 3 NH 3 PbI 3 ) is used extensively as the absorber material for both solar cells and photodetectors; however, the reported photodetectors are all planar and flexible planar devices. To the best of knowledge the first flexible wire-shaped perovskite photodetector is reported. The performance of the wire-shaped perovskite photodetector on carbon nanotube yarn (CNY) critica...

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High quality triple cation perovskite thin films realized through the combination of the anti-solvent bath method and low temperature annealing.

Self-powered photodetectors (PDs) are suitable for application in smart systems, image sensing and optical communications. Herein, a self-powered PD based on triple cation lead-halide perovskite (TCLP) is reported. We showed the effect of bromide concentration on the optical and structural properties of the TCLP films. Additionally, an environmental stability test was conducted and it was found that TCLP with 10% Br can remain stable for up to 128 days after exposure to ambient air. Using this material, a self-powered perovskite PD was fabricated and demonstrated an impressive performance with a responsivity of 0.52 A W −1 , detectivity of 8.8×10 12 Jones, on/off ratio of 7.3×10 5 , and a rapid rise and decay time of 19 μs and 21 μs, respectively. This work offers a useful insight into the effects the fabrication method of the thin film plays in building low-cost, stable, and high-performance self-powered PDs for application in structural health monitoring, imaging, optical communication, and biomedical sensing.