Fabrication And Study On Properties Of Nano LED Array Modulated By Strain Coupling Effect

In recent years,tactile sensors have attracted extensive attention as an important component for sensing external stimulation signals in intelligent electronic devices and electronic skin.In tactile sensor,signal transmission is mainly realized by electrical signal and optical signal,and optical signal has the advantages of visualization,fast response speed and low crosstalk.Therefore,using optical signal to realize the distributed sensing of pressure signal is one of the hotspots of tactile sensor research.Using the change of luminous intensity caused by piezoelectric potential of piezoelectric LED array to realize mechanical electro-optical coupling is a very effective strategy to realize optical signal tactile sensing.However,it is still a great challenge to prepare piezoelectric LED array devices with high luminous performance and expand the electromechanical optical coupling mechanism from piezoelectric materials to the first generation semiconductors such as silicon.In this paper,we constructed NPB / Cd Se QDs / Zn O based on Zn O nanowires and p-Si / Cd Se QDs / TPBi QLED array based on Si micropillars.Piezoelectric effect and strain coupling effect are introduced to modulate the luminescence performance of QLED array devices,and the modulation mechanism are studied.The specific research contents include:(1)ZnO nanowires array was obtained by photolithography and low-temperature hydrothermal method.Combined with the excellent optical properties of quantum dot materials,QLED array devices based on Zn O nanowires were constructed,and their morphology and photoelectric properties were characterized.The piezoelectric potential generated by Zn O nanowires under compressive stress enhances the light emission intensity of local luminous pixels.This work realizes the visual mapping of pressure distribution through QLED array,which will be widely used in future intelligent fields such as electronic skin.(2)Si micropillars array was obtained by photolithography and ICP etching.Firstly,the influence of strain coupling effect on the electrical characteristics of Si micropillars array under external compressive stress was studied.Then,the QLED array devices based on Si micropillars were fabricated,and its morphology and photoelectric characteristics were characterized.Finally,the strain coupling effect of Si micropillars was used to enhance the light emission intensity of local pixels under pressure.The light emission intensity of pixels increases about 6 times under the pressure of about 13.8 GPa.This extends the mechanical electrical optical coupling mechanism,which has been limited to piezoelectric materials,to silicon materials,which currently plays a leading role in the semiconductor industry,and realizes the performance modulation of silicon-based light-emitting devices by using pressure.It is expected to realize visual pressure distribution imaging in silicon-based QLED array,which provides a new idea for the large-scale integration of silicon-based photonic devices and the research of silicon-based optical interconnection systems,and shows the potential application prospects in the fields of electronic skin and electronic signature.