Fabrication And Photoemission Theory Of GaAs Nanowire Arrays Photocathode

Gallium arsenide(GaAs) nanowire arrays has attracted much attention due to their unique electrical and optical properties, and the related research in nanoelectronics, nanophotonics, and nanogenerators. Top-down etching techniques have been used for fabricating much larger nanowire arrays for a long time with complex vertical structures, and it has been succes to etch structures down to nanoscale with high quality. Although the application of GaAs photocathode materials and GaAs nanowire arrays has made great achievements, but the study on the negative electron affinity potential GaAs nanowire arrays photocathode is still not been reported. In this work, we performed some thorough studies on GaAs array fabrication, characterization techniques, cathode activation process.In this paper, we use the top-down dry etching technology based on inductively coupled plasma(ICP) to prepare GaAs nanowire arrays. We use scanning electron microscopy(SEM), rapid thermal annealing technology and room temperature photoluminescence(PL) technology investigated the effects of photoresist, chemical cleaning, annealing temperature, preparation technology on the preparation of GaAs nanowire arrays. Based on the comprehensive consideration of the various affecting factors, we design and optimize the dry etching processes for GaAs nanowire arrays.Using the integrated test system of GaAs nanowire array photocathodes, we study the effects of light incidence angle, chemical cleaning, nanowires size on GaAs nanowire array photocathodes. We analyze the characteristics of GaAs nanowire array photocathodes according to the spectral response curves. Finally, the optimized fabrication processes for GaAs nanowire array photocathodes are achieved.