Field emission and field ion microscopy from single crystal diamond needle

Needle-like single crystal diamond structures were obtained by combination of the plasma enhanced chemical vapor deposition (CVD) and selective oxidation techniques. Field emission currents and total electron energy distributions were measured for individual diamond needles as functions of extraction voltage and the intensity of the femtosecond laser focused on the needle. Moreover, a new set-up based on the coupling of a field ion microscopy (FIM) with an ion energy analyser (ionic lens) is used to measure voltage drops lower than 1%. The needles demonstrate current saturation phenomenon and emission sensitive to laser intensity. The analysis of the voltage drops measured via electron energy analyser and FIM shows that the conduction is governed by Poole-Frenkel transport mechanism at low laser intensity. Based on experimental observations, the laser contribution to conduction mechanisms is discussed.