【作者】 张亚萍；

【导师】 叶腾凌；

【作者基本信息】 哈尔滨工业大学 ， 应用化学， 2020， 硕士

【摘要】 近年来,金属卤化物钙钛矿纳米材料因其发射光谱可调、荧光量子产率高、制备方法简单、成本低等优势,在太阳能电池、电致发光二极管、场效应晶体管、激光器、存储器等领域均具有独特的应用价值,引起了广泛关注。考虑到铅基钙钛矿的毒性,及对水、热、光等因素的敏感性,开发非铅稳定的钙钛矿材料的研究成为该领域的热点。本文基于环境稳定的四价锡,分别制备了一系列具有不同形貌的Cs₂SnI₆类钙钛矿纳米材料和一种（OLA）_xSnI₄类钙钛矿量子点荧光材料,对材料的结构、形貌、光电性质及应用进行了表征分析。目前已报道的Cs₂SnI₆纳米材料主要以传统热注入法来制备,该方法合成过程复杂,且对制备环境和制备工艺要求较高,不易控制和大规模放大合成。在借鉴铅基钙钛矿纳米材料制备方法的基础上,本论文首先探索一种简化的“溶剂热法”通过改变配体比例和用量对其形貌进行了调控,制备了一系列Cs₂SnI₆纳米材料。其中当油胺油酸等比例时,可获得一种超薄的Cs₂SnI₆二维材料,其展示了很好的环境稳定性,XRD结果表明在空气中放置270天未见明显分解,稳态光电压测试估算材料带隙为1.62 eV,瞬态表面光电压结果表明该材料为n型半导体。而后,将不同形貌的Cs₂SnI₆纳米材料作为活性层,制备了一种结构为ITO/PMMA/Cs₂SnI₆/Al₂O₃/Ag的非易失性阻变存储器,最优器件开光比超过1000,ON/OFF态电流在循环600次后未见明显衰减,在2 V的恒定电压下ON/OFF态电流保持时间超过10000 s,展现出很好的器件稳定性。此外,本文以SnI₄和OLA为反应原料,利用三种不同的反应条件（“加热并搅拌”,“搅拌”和“超声”）,一步制备出了同一种新型锡基类钙钛矿（OLA）_xSnI₄量子点荧光材料,从加热并搅拌”到“超声”,材料的平均粒径逐渐增大,依次为2.67 nm、3.2 nm和4.0 nm,“加热并搅拌”制备的材料结晶性较后两种差。不同条件制备出的（OLA）_xSnI₄量子点在紫外灯下表现出橙光发射,PL光谱发射峰位置相同,均在582 nm,616 nm,653 nm,694 nm处有明显的发射峰。更多还原

【Abstract】 In recent years,metal halide perovskite nanomaterials have been attracted widespread attention since the adjustable emission spectrum,high fluorescence quantum yield,simple preparation method and low cost.And metal halide perovskite nanomaterials have unique application value in the field of solar cells,electroluminescent diodes,field effect transistors,lasers and switching devices.Considering the toxicity of lead-based perovskites and the sensitivity to water,heat,light and other factors,developing non-lead-stabilized perovskite materials have become a hot topic in this field.In this paper,a series of Cs₂SnI₆ perovskite nanomaterials with different morphologies and an（OLA）_xSnI₄ perovskite quantum dot fluorescent material were prepared based on the stable tetravalent tin in the environment.The photoelectric properties and applications were characterized and analyzed.Generally,most reported Cs₂SnI₆ nanomaterials are mainly prepared by the traditional "hot injection method".However,the synthesis process of this method is complicated,and has high requirements on the preparation environment and preparation process,which is not easy to control and large-scale synthesis.Based on the preparation method of lead-based perovskite nanomaterials,actively explore a new and simplified solvothermal preparation process to prepare Cs₂SnI₆ nanomaterials,and propose to change its morphology and stability by changing the proportion and amount of ligands.Among them,when the ratio of oleylamine and oleic acid is equal,an ultra-thin Cs₂SnI₆ two-dimensional material can be obtained,which shows good environmental stability.The XRD results show that there is no obvious decomposition after being left in the air for 270 days,and the steady-state photovoltage The test estimates that the band gap of the material is 1.62 eV,and the transient surface photovoltage results indicate that the material is an n-type semiconductor.Then,using Cs₂SnI₆ nanomaterials with different morphologies as the active layer,a non-volatile resistive memory with the structure of ITO/PMMA/Cs₂SnI₆/Al₂O₃/Ag was prepared.The current did not decay significantly after 600 cycles.At a constant voltage of 2 V,the ON/OFF state current retention time exceeded 10000 s,demonstrating good device stability.In addition,in this paper,SnI₄ and OLA were used as reaction raw materials,and the same new tin-based perovskite（OLA）was prepared in one step using three different reaction conditions（"heat and stir","stirring" and "ultrasonic"）.The SnI₄ quantum dot fluorescent material,from heating and stirring" to "ultrasonic",the average particle size of the material gradually increases,followed by 2.67 nm,3.2 nm and 4.0 nm,the material prepared by "heating and stirring" is more crystalline than the latter two Poor.（OLA）_xSnI₄ quantum dots prepared under different conditions show orange light emission under ultraviolet lamp,and the emission peak positions of PL spectrum are the same,all have obvious emission peaks at 582 nm,616 nm,653 nm,and 694 nm.更多还原