Transferring Preparation Of Large-scale Nano-graphene Film Over Semiconductor Substrate And The Photoelectric Characteristics

The development of nano-meter graphene technology indicates that the graphenewith several or even one single atomic-layer of carbon structure, is a noveltwo-dimensional material with extraordinary optical, photoelectric, and electronicproperties. The intrinsic nano-meter graphene material has very high optical transmittanceand electronic mobility as a zero-band gap semiconductor material. According to itsspecial zero-band gap and ultra-wide spectrum properties, the nano-meter graphene can beused in the next generation of photodetection, and then as a kind of photoelectricfunctional material can also be used in other important opto-electronic applications.Because of the very high optical transmittance and excellent electrical conductivity, thegraphene can be used as a good substitute for transparent electrode such as traditionalIndium tin oxide (ITO). So, the patterned graphene mask can be applied in wireless powertransmission and controlling system of electrically controlled liquid crystal (LC) lens as akind of ultra-wide spectrum, very high conductivity, and ultra-thin transparent electrode.In this paper, we firstly present the technique of transferring large-scale graphenefilm of about1cm2from Cu substrate onto the semiconductor wafers such as Si, GaAs,etc. We research the electrical property of graphene film over different semiconductorwafers. The experiments show that the large-scale transferred graphene film fabricated byspin-coating method demonstrate required integrity and surface resistance in the range of1kΩ/sq～10kΩ/sq, and the transparency of more than~80%in the visible range.Utilizing the transferred graphene films acquired, we fabricate the graphenemicro-patterned structures over different semiconductor wafers, and further research thephotoelectric properties of graphene mask acquired. The graphene microstructures consistof the transferred graphene film over IR wafers used and metal wires contacted withgraphene mask and outside electrical set-ups utilized. In our studies, the current-voltagerelationship of the graphene microstructure is measured before and after illumination ofinfrared laser beam. The tests show that the laser beam illumination can effectivelyimprove the photocurrent gain and the significant changes of current-voltage performanceof the graphene microstructure over different substrates. Because the pure single atomic-layer graphene demonstrates a special highelectronic mobility of～2×10~5cm~2/Vs and very high optical transparency of~97.7%, it isclear that the graphene films will show a big advantages as a new type of transparentelectrode correspondent to ITO electrode material. We fabricate the patterned graphenemask with micron-scale linewide using photolithography and ion beam lithographymethod, and measure and analyze the microstructural characters of the patterned graphenemask, and further design and fabricate the graphene microcoils for wireless powertransmission and controlling set-ups of electrically driving liquid crystal microlenses.