Flexible Wire‐Shaped Perovskite Photodetector via Joule Heating for Improved Crystallization and Performance

Abstract

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...

Flexible Ultrathin Single-Crystalline Perovskite Photodetector

“…Comparing with recently reported flexible perovskite photodetectors working in the visible range (summarized in Table ), our flexible photodetector exhibits several characteristics: (i) Ultrathin active layer with 20 nm in thickness, which is the thinnest flexible perovskite photodetector to the best of our knowledge. (ii) High responsivity up to 5600 A/W, much higher than that of previously reported flexible perovskite photodetectors for 2 orders of magnitude, − which demonstrates the remarkable detection efficiency of the photodetector. (iii) Fast response with the rise/fall time of 3.2/9.2 μs, which gives rise to an outstanding 3 dB bandwidth up to 0.2 MHz.…”

Band Engineering of Carbon Nanotubes for Device Applications

“…Regarding other aggregates, Adams et al recently reported CNT yarns with organolead triiodide perovskite wrapped as wire-shaped heterostructures, which can be used as self-powering photodetectors with high performance. 69 Wang and Kumta reported the synthesis of heterostructures consisting of CNT vertical arrays and nanoscale amorphous/nanocrystalline Si droplets using a simple two-step liquid-injection CVD process, which has potential for use in high-capacity Li-ion anodes. 70 Therefore, according to the special band structures of CNTs, proper band engineering based on the target device is necessary.…”

Depleted Sb2S3 Thin Film Photoconductive Detectors with Fast Response Speed and High Polarization Sensitivity

“…Thin film PDs play important roles in video imaging, optical communication, and environmental monitoring. [1][2][3][4][5][6][7][8] Antimony sulfide (Sb 2 S 3 ), a binary compound, has a single phase, a large content, and is non-toxic. The suitable bandgap of 1.73 eV and the absorption coefficient greater than 10 5 cm −1 in the visible light range make In this work, we design a depleted Sb 2 S 3 thin film photoconductive detector with the structure of Au/(glass/TiO 2 :) Sb 2 S 3 /Au by introducing a TiO 2 layer between the Sb 2 S 3 film and the glass substrate.…”