All Inorganic Cesium Lead Iodide Perovskite Nanowires with Stabilized Cubic Phase at Room Temperature and Nanowire Array-Based Photodetectors

Abstract

Alluring optical and electronic properties have made organometallic halide perovskites attractive candidates for optoelectronics. Among all perovskite materials, inorganic CsPbX (X is halide) in black cubic phase has triggered enormous attention recently owing to its comparable photovoltaic performance and high stability as compared to organic and hybrid perovskites. However, cubic phase stabilization at room temperature for CsPbI still survives as a challenge. Herein we report all inorganic three-dimensional vertical CsPbI perovskite nanowires (NWs) synthesized inside anodic alumina membrane (AAM) by chemical vapor deposition (CVD) method. It was discovered that the as-grown NWs have stable cubic phase at room temperature. This significant improvement on phase stability can be attributed to the effective encapsulation of NWs by AAM and large specific area of these NWs. To demonstrate device application of these NWs, photodetectors based on these high density CsPbI NWs were fabricated demonstrating decent performance. Our discovery suggests a novel and practical approach to stabilize the cubic phase of CsPbI material, which will have broad applications for optoelectronics in the visible wavelength range.

Recent advances on organic‐inorganic hybrid perovskite photodetectors with fast response

“…However, owing to large specific surface area, defect‐free single crystal and high crystal quality. Photodetectors composed of nanowires and nanorods have higher response speed than those of the conventional single crystal photodetectors . Until now, several research groups obtained the μs‐level response speed using nanowire or nanorod structures respectively.…”

Low‐dimensional metal halide perovskites and related optoelectronic applications

“…In their demonstration, MAPbI 3 nanowires with diameters ranging from 50 to 200 nm, with a dispersity less than 10%, were synthesized readily. Later, Waleed et al combined the vapor‐phase process with this template confinement method, fabricating lead‐free and inorganic perovskite nanowires with a start from pure metals (Figure B) . To be specific, AAO membranes were still chosen as the template, and metal tin or lead was electrochemically deposited in the bottom of the nanopores.…”

“…To be specific, AAO membranes were still chosen as the template, and metal tin or lead was electrochemically deposited in the bottom of the nanopores. MAI or CsI gas, produced by heating the corresponding powders, were transported by the carrier gas and reacted with the as‐deposited metal, facilitating the forming of final MASnI 3 or CsPbI 3 nanowires (Figure B,C) . Oener et al devised a nanowire extrusion method where precursor was first dropped on the AAO templates with double‐sided pores.…”

“…Utilizing the morphological anisotropy of nanowires, Gao et al demonstrated a photodetector with high polarization sensitivity and detectivity (2 × 10 13 Jones) for the first time . Considering the instability issues, several groups moved interests onto the inorganic counterparts . Waleed et al used the AAO templates to fabricate CsPbI 3 nanowire‐based photodetector, showing high stability when stored in organic polar solvents for 30 days .…”

“…Considering the instability issues, several groups moved interests onto the inorganic counterparts . Waleed et al used the AAO templates to fabricate CsPbI 3 nanowire‐based photodetector, showing high stability when stored in organic polar solvents for 30 days . Zhang et al formed a thin CsPbBr 3 ‐nanowires based photodetector, showing a sensitive photoresponse (Figure D) .…”