Preparation And Performance Study Of Perovskite Nanowire Arrays Based On Aluminum Oxide Templates

In recent years,researchers have tried to combine nanostructures in optoelectronic devices,which can effectively improve the photoelectric performance of devices.As a new generation of optoelectronic materials,perovskite nanomaterials have the advantages of high light absorption coefficient,carrier mobility and large diffusion length,which is one of the research hotspots in the field of optoelectronic devices.At present,the research on perovskite nanomaterials mainly focuses on perovskite thin films,and there are few studies on perovskite nanowires.This paper combines alumina template and chemical vapor deposition to prepare perovskite nanowire arrays.The main research can be divided into two aspects.First,lead nanowires are electrodeposited based on anodic alumina（AAO）template.On this basis,CH₃NH₃Pb I₃ nanowires were grown by chemical vapor deposition using lead and methylamine iodine embedded in AAO template,and the properties of CH₃NH₃Pb I₃ materials were tested.Firstly,in theory,this paper uses Faraday’s law of electrolysis to calculate the time when the deposited lead fills the nanopore of the template,and explores the process parameters of preparing lead nanowires using AAO template.Lead nanowires were deposited by direct current electrodeposition and alternating current electrodeposition using single-pass AAO and double-pass AAO as templates,respectively.There is a barrier layer at the bottom of the single-pass AAO template.The hydrogen evolution reaction is serious by direct current deposition,and it is difficult for lead to deposit into the hole in a large area.The current density of pulse electrodeposition is 8m A/cm2,and the hydrogen evolution reaction slows down to disappear,which improves the length of lead nanowires and the filling rate of AAO template.There is also a hydrogen evolution reaction during the direct current deposition of the double-pass AAO template.Instead of pulse electrodeposition,the current density is 2m A/cm2,which improves the growth quality and length of lead.However,the template needs additional gold plating to increase conductivity,and the template is not aluminum-based.The support is brittle,which increases the difficulty of experimental operation.Subsequently,the photoelectric properties of CH₃NH₃Pb I₃ materials were characterized.The CH₃NH₃Pb I₃ films were prepared by solution method and the absorbance was tested.The experimental results show that the light in the 400nm-800nm band has a strong absorption capacity and can be used as an excellent photoelectric material for detecting the visible light band.At the same time,CH₃NH₃Pb I₃ nanowires were prepared on the inclined substrate by solution method.Experiments show that different sizes of CH₃NH₃Pb I₃ nanowires can be obtained by adjusting the concentration of the solution.As the concentration of the solution decreases,the size of the nanowires gradually decreases.When the concentration is 0.1wt%,the width of the nanowires is about 1μm,and the nanowires are mostly intermittent and cannot form longer continuous nanowires.After that,gold electrodes were evaporated at both ends of the nanowires,and the current was measured at the n A level.With the increase of light intensity,the current also increased,and there was obvious photoelectric performance,which verified the feasibility of using CH₃NH₃Pb I₃ nanowires to construct photoelectric devices.Finally,CH₃NH₃PbI₃ nanowires were prepared by tube furnace based on AAO template deposited metal lead,and the photoelectric properties of nanowires were tested after evaporation of electrodes.In this paper,high-quality CH₃NH₃Pb I₃ nanowires were prepared by heating the AAO template with lead deposition and methylamine iodine powder in a tube furnace.Subsequently,a gold electrode was evaporated on the surface of the AAO template embedded with CH₃NH₃Pb I₃ nanowires to form a photodetector,and linear sweep voltammetry was applied to measure its volt-ampere curve under light and dark.Due to the difference in work function of Al,Au and CH₃NH₃Pb I₃,the device prepared by single-pass AAO template has a band bending,resulting in an asymmetric I-V curve.In this paper,CH₃NH₃Pb I₃ nanowires were successfully prepared by using alumina template combined with electrodeposition and chemical vapor deposition.On this basis,photoelectric devices were constructed and their photoelectric properties were tested.