Electrical conduction mechanism in laser deposited amorphous carbon

The electrical conduction mechanism in the high electric field region of pulsed laser deposited amorphous carbon has been studied. Carrier transport through the films is found to be via a Poole–Frenkel type conduction hopping process for electric fields greater than 4 × 104 V/cm. The dielectric constant extracted from the Poole–Frenkel equation and the square of the refractive index evaluated from ellipsometry show comparable values of around 5. The activation energy for current transport through the films and the product of trap density and mobility is found to be dependent on the laser energy density.