DEFECT-ENHANCED ELECTRON FIELD-EMISSION FROM CHEMICAL-VAPOR-DEPOSITEDDIAMOND

Diamond samples with varying defect densities have been synthesized by chemical vapor deposition, and their field emission characteristics h ave been investigated. Vacuum electron field emission measurements ind icate that the threshold electric field required to generate sufficien t emission current densities for flat panel display applications (>10 mA/cm(2)) can be significantly reduced when the diamond is grown so as to contain a substantial number of structural defects. The defective diamond has a Raman spectrum with a broadened peak at 1332 cm(-1) with a full width at half maximum (FWHM) of 7-11 cm(-1). We establish a st rong correlation between the field required for emission and the FWHM of the diamond peak. The threshold fields are typically less than 50 V /mu m and can reach as low as 30 V/mu m for diamond with a FWHM greate r than 8.5 cm(-1). It is believed that the defects create additional e nergy bands within the band gap of diamond and thus contribute electro ns for emission at low electric fields. (C) 1995 American Institute of Physics.