Fabrication Of Large-area And High-performance Film Photodetector Arrays

Film photodetectors are widely used in the fields of communication?military?fire alarm?aviation and aerospace Because of its high responsivity and fast response rate.In recent years,with the development of the wearable equipment,the folding and the bending equipment,people not only need to improve the responsivity,response rate and detection rate,but also need to find new materials to meet wearable equipment,folding,bending equipment and other higher requirements.Focusing on these issues,two directions were studied in this dissertation.(1)14-inch graphene was synthesized on Cu foil by chemical vapor deposition(CVD)method,and then the CVD-grown graphene was successfully transferred onto PMMA/AB-glue/PET substract without the removal of polymer by a crackless transfer method without the removal of polymer.The graphene not only has a good integrity,but also has a narrow distribution and falls into the range of 200-500 ? sq-1 with the lowest value of 219 ? sq-1,further more,The transmittance of graphene/PMMA/AB-glue is 96.5%.The photodetector based on ZnSe ribbon/graphene not only has higher photocurrent,higher responsivity,higher detectivity and shorter response time,but also the integrated flexible photodetector arrays can be used as a high uniformity and high performance image sensor.However,while the photodetector arrays were bended for three times,photocurrent has a large decline.After bending three times,the photocurrent decreases slowly and reaches a steady state,it indicates that the mechanical durability of the ZnSe/graphene/PMMA/ABglue/PET flexible photodetector arrays is not good enough,this needs further improvement.(2)Interface-confined epitaxial growth of non-layer structured NiSe films with grain size up to micron scale on Ni foil has been achieved by means of solid-state reaction between ZnSe film and Ni foil,the mechanism of NiSe film growth was proved that NiSe is formed by means of the inter-diffusion of Zn and Ni after characterizations.NiSe film based photodetector arrays which were fabricated by patterned growth and transfer of NiSe films are not only desired for the integration of photodetectors into sensing and imaging systems,but also shows a responsivity of 150 A/W much higher than the photodetector based on asdeposited NiSe film consisting of nanocrystals,showing a huge responsivity-enhancement up to 4 orders of magnitude.