Research On High-performance Flexible Electronic Devices Based On Nanostructures

With the development of modern science and technology,flexible electronic devices are developing towards miniaturization,integration,and high performance,and are widely used in the fields of robots,wearable electronic devices,and human-machine interaction to make great changes at many aspects of human life.Conventional flexible electronic devices are implemented through conductive organic molecular/polymer materials and the microstructure design of inorganic metal materials,but they are still generally immature and remain many problems,such as poor performance and unstable operation.It is urgent to develop highperformance flexible electronic devices to meet the human requirements.Benefiting from the quantum size effect,nanomaterials possess excellent physical properties rather than traditional bulk materials and provide a new route to develop high-performance flexible electronic devices.In this paper,the basic semiconductor materials,conductive electrode materials and basic components of flexible electronic devices are systematically studied using micro-nano assembly technology in experiments and theoretical analysis.Firstly,the singular properties of semiconductor nanostructures in atmosphere were characterized.Based on the advantages of nanostructures in mechanical properties,the design,assembly and performance of flexible electrodes and flexible devices based on nanostructures are explored further.The main works of this dissertation includes the following aspects:In the aspect of basic semiconductor materials,the mechanical properties of onedimensional ZnO nanowires and two-dimensional perovskite in the atmosphere were studied by using nanowires resonator and corrected atomic force scanning method,respectively.Further,the "core-shell" model and "sandwich" model are constructed to study the change of mechanical properties with nano size in the atmosphere.It provides reference for the design and application of nanomaterials in flexible electronic devices.In the aspect of interconnection electrode,the high transparent flexible electrode based on silver nanowire network and the high bending flexible electrode based on nano-wave structure were prepared by using electrospinning,nano imprinting,and other technical methods.The mechanical and electrical properties of the two electrodes were studied by numerical simulation and experimental methods,and the excellent properties of 50%stable extensibility and more than 90%light transmittance were achieved.In addition,a transparent haptic system with high stretchability and transparency and a foldable motion monitoring system with excellent stable electrical properties have been realized respectively,which shows the application advantages of flexible electrode based on nanostructure.In the aspect of basic electronic devices,a fantastic flexible transistor with highperformance nanowire channel and organic photodiode gate is realized,which gets rid of the limitations of the structure of channel and gate in traditional field effect transistor.This method of photo-triggered gate provides an alternative method for the realization of flexible logic circuits by controlling channel carrier to achieve transfer characteristics.Further,a highperformance pressure transistor is achieved using the piezoelectric nanowires,and a flexible electrical skin based on the transistor array is fabricated experimentally with the dynamic range of about 120 dB and the sensitivity of up to 61.2 S/kPa,which demonstrates the application value of flexible electronic devices based on nanostructures in this field.