The Fabrication Of Metal Nanostructures On Flexible Substrates And Integrated Technology With Semiconductor Light Emitting Devices

Flexible materials,such as polydimethylsiloxane(PDMS),Polycarbonate(PC),Polymide(PI),etc.,are used to make stretchable and wearable flexible devices due to their incomparable superior characteristics of a variety of rigid materials,which are widely applied in energy,medical,information,national defense and other fields.Semiconductor light-emitting devices,such as light Emitting Diode(LED),Vertical Cavity Surface Emitting Laser(VCSEL)have the characteristics of emitting light perpendicular to the substrate,thus facilitating the integration into a large-area,high-density two-dimensional array.They have important applications in lighting,sensing,optical communication and other fields.In this paper,the fabrication of metal nanostructures on PDMS substrates and the integrated technologies with LED and VCSEL are studied,and the sensing applications of integrated chips are explored.The main research contents are as follows:(1)Metal nanostructures were fabricated on PDMS substrate rapidly,large area and low cost: Periodic gold nanostructures such as gratings,dot and hole arrays were prepared on PDMS by laser interference lithography.The gold nanostructures of PDMS substrates were prepared by using self-assembly of silicon dioxide spheres,the pre-groove structure in Polycarbonate(PC)of DVDs and the AAO films.These gold nanostructures show the characteristics of surface plasmonic which are sensitive to the refractive index,and can be used for biochemical sensing.(2)The preparation of semiconductor light-emitting devices and their integration with metal nanostructures of flexible substrate: Red LED with peak wavelength of 626 nm and 4×4 high-power oxidized VCSEL array with laser wavelength of 850 nm were prepared.Silicon templates were fabricated by photolithography,and PDMS microfluidics were fabricated by revealing the PDMS after curing.The bonding process was firstly used to bond the PDMS microfluidic and the flexible substrate metal nanostructures;and then LED and VCSEL arrays were bonded in the secondary bonding to integrate flexible metal nanostructures and semiconductor light-emitting devices.(3)Test and analysis of semiconductor light emitting devices with metal nanostructures on integrated PDMS substrates: Based on the sensitivity of surface plasmons of noble metal nanostructures to environmental refractive index,the integrated chips were tested and their sensing applications were explored.The transmission spectrum of metal nanostructures on PDMS substrates were measured by injecting different refractive index liquids into microfluidics.The optical power and spectrum of VCSEL integrated chips were also measured.Finally,the qualitative judgment of different liquids was explored by using the visual changes of LED integrated chips.In this paper,gold nanostructures are fabricated on PDMS,which is easy to bond with most commonly used semiconductor materials.Then,they are bonded with low-cost,easy-to-integrate semiconductor light emitting devices such as VCSEL and LED to realize refractive index sensing through the surface plasmon characteristics of gold nanostructures.This method is more advantageous than the conventional method of fabricating nanostructures directly on light emitting devices.The excitation and sensing functions of Miniaturized Total Analysis Systems(?TAS)are preliminarily realized.The system has the advantages of real-time,low cost and unlabeled.