【作者】 郭丽霞；

【导师】 付永明；

【作者基本信息】 山西大学 ， 电子信息， 2023， 硕士

【摘要】 压电光电子效应是存在于非中心对称结构半导体中的压电、光激发和半导体特性的三重耦合效应,在提高光电材料和器件的量子产率方面具有巨大发展潜能,从而有助于提高能量转换效率,缓解当前人类面临的各种能源短缺危机。构建异质结可以通过界面处发生的能带偏移为高性能器件的设计提供强有力的工具。因此,构建异质结型压电半导体材料,研究异质结材料中的压电光电子效应,对推动压电光探测和压电光催化的应用具有重要意义。面对当前光学技术的快速发展,迫切需要开发具有良好光响应性、稳定性、柔韧性和小型化的新型光探测器。在本文第二章研究中,采用静电纺丝法合成了Zn O-Sn O₂异质结纳米纤维作为光敏材料,与PI基板上的光刻图案微电极结合,制备了微型柔性紫外探测器。Zn O-Sn O₂异质结界面存在大面积Zn₂Sn O₄层以阻碍电荷迁移,其暗电流低至约10^-11A。在功率密度为24μW cm^-2的紫外光照射下,光探测器响应度高达267A W^-1,快速响应时间为2.75s。该光探测器具有良好的光电性能和较高的紫外选择性,以及较好的柔韧性。即使在45^°的大弯曲角下,光响应仍保持初始水平的60%。压电光催化是探索压电场与载流子相互作用的重要成果之一,在染料降解、水分裂制氢和杀菌等方面具有潜在的应用前景。虽然研究人员已经开发出多种异质结催化剂以提高光催化能力,但形貌对光催化性能的重要影响一直没有得到重视。本文第三章研究中,在不锈钢网上合成刷状Zn O纳米棒阵列,然后硫化成Zn O-Zn S核壳纳米棒阵列,发现硫化后的压电光催化降解率从25.1%提高到45.4%。进一步地,在不影响Zn S纳米颗粒壳层分布的情况下,将Zn O-Zn S纳米棒蚀刻成Zn O-Zn S纳米管,压电光催化降解率进一步提高到63.3%。结合电子自旋共振研究和数值模拟分析,证明了相较于棒状异质结,管状异质结可以有效增强压电场的耦合效应,减少电荷迁移距离,并抑制光激发电子-空穴对的重组。更多还原

【Abstract】 The piezoelectric photonic effect is a three-way coupling effect of piezoelectric,optical excitation and semiconductor properties in non-central symmetric semiconductors.It has great development potential in improving the quantum yield efficiency of photoelectric materials and devices,thereby helping to improve the efficiency of energy conversion and alleviate various energy shortage crises faced by mankind.The construction of heterojunctions can provide a powerful tool for the design of high-performance devices through the band shift occurring at the interface.Therefore,the construction of heterojunction piezoelectric semiconductor materials and the study of piezoelectric photoelectronic effects in heterojunction materials are of great significance to promote the application of piezoelectric photodetection and piezoelectric photocatalysis.Developing new photodetectors with good photoresponse,high stability,flexibility,and minimalization is urgently demanded facing the rapid development of optical technology.In Chapter two,Zn O-Sn O₂ heterojunction nanofibers are synthesized by electrospinning.The flexible UV micro-photodetector is fabricated by combining Zn O-Sn O₂ heterojunction nanofibers with photolithography-patterned Au microelectrodes on PI substrate.An extremely low dark current(～10^-11 A)is obtained due to the formation of Zn₂Sn O₄ layer at the large interface of Zn O-Sn O₂ heterojunctions.Upon exposure to UV light with power density of 24μW cm^-2,the photodetector exhibits high on–off ratio of～10⁴,high responsibility of 267 A W^-1,and fast response speed of 2.75 s.The photodetector has good photoelectric properties and high UV selectivity.Moreover,the flexibility of the UV photodetector is demonstrated.The photoresponse remains～60%of the initial level even under a large bending angle of 45^°.The combined utilization of electrospinning and photolithography is convenient to fabricate flexible UV photodetectors.Sonophotocatalysis is one of the most significant outcomes of the exploration of the interaction between piezoelectric field and charge carriers,which exhibits potential applications in dye degradation,water splitting,and sterilization.Although several heterojunction catalysts have been applied to improve the sonophotocatalytic capability,the importance of the morphology on the sonophotocatalytic capability has not been emphasized.In this study,brush-like Zn O nanorod arrays are synthesized on a stainless-steel mesh and subsequently vulcanized into Zn O-Zn S core-shell nanorod arrays to investigate the sonophotocatalytic capability of the heterojunction.The sonophotocatalytic capability increases from 25.1%to 45.4%through vulcanization.Afterward,the Zn O-Zn S nanorods are etched to Zn O-Zn S nanotubes without affecting the crystallography and distribution of the Zn S nanoparticle shell,further improving the capability to 63.3%.In Chapter 3,The improvement can be ascribed to the coupling effect of the enhanced piezoelectric field and the reduced migration distance,which suppresses the recombi-nation of photoexcited electron–hole pairs while transforming the morphology from nanorod to nanotube,as proven by the electron spin resonance test and numerical simulations.This study explores a novel approach of morphology engineering for enhancing the sonophotocatalytic capability of heterojunction nanoarrays.更多还原