Modified diamond micropyramid arrays for field electron emission and electronic devices

Results on structural modifications of diamond micropyramid arrays for impr oved field electron emission are reported. Arrays of pyramids were prepared using a molding technique. As-grown CVD diamond pyramids 9 microns in size with sharp apexes were insulating in behavior and showed a relatively poor field electron emission. Several methods are examined to enable electrical conductivity of diamond in order to supply electrons for the emission: dia mond boron doping, partial graphitization/amorphization by nitrogen ion imp lantation and/or high-temperature annealing, formation of a metal subsurfac e layer, and the use of composite diamond/graphite materials instead of CVD diamond. An improvement of surface electrical conductivity and a reduction of field electron emission thresholds down to 5-10 V/mum was observed. The results are explained by taking into account the geometric field enhanceme nt on pyramid apexes.