Light penetration depth dependence of photocarrier life time and the Hall effect in phosphorous-doped and boron-doped homoepitaxial CVD diamond films

Photocurrent in phosphorous-doped CVD diamond film of the bandgap of 5.5 eV with the density of 2 × 1018 cm− 3 decreases with increasing photon energy in the energy range higher than 5.8 eV at room temperature (RT). The photocarrier life time is 0.3 ms at the excitation energy of 5.8 eV and decreases with increasing excitation energy. These show that the photocarriers, ascertained to be electrons by the Hall effect of the photocurrent, are trapped near the surface. The life time of photo-excited holes in Boron-doped CVD diamond film with the density of 9 × 1017 cm− 3 is 35 ms at RT and decreases with decreasing Boron density, which is explained from the relation between the Fermi energy and the density.

► Photocarrier life time in the homoepitaxial CVD diamond films is observed.
► Photocarriers in the P-doped CVD diamond film are electrons.
► Photo-electrons in the P-doped diamond film are trapped near the surface.