Enhancement of photosensitivity by ultraviolet irradiation and photoconductivity spectra of diamond thin films

Abstract

The evolution of photocurrent in time under ultraviolet (UV) irradiation of free-standing diamond thin films, prepared by chemical vapor deposition method, have been observed. A significant enhancement of the photosensitivity in visible-near-infrared region of UV illuminated samples have been obtained. The linear dependence of relative change of photocurrent on UV radiant intensity have been found. The photoconductivity spectra have been investigated in the energy range 1–6.2 eV. The results of investigation have shown that diamond thin films possess similar properties as radiation damaged crystalline diamond.

Defect structure, distribution, and dynamics in diamond-on-silicon optoelectronic devices

“…21,31 We observed these effects in unoriented samples, as shown in Fig. 21,31 We observed these effects in unoriented samples, as shown in Fig.…”

“…30,31,35 The same slow kinetics is followed when light is removed. Indeed the current of an as-grown randomly oriented sample under UV illumination reaches the steady-state condition after a few hours, as reported by several authors.…”

Thermally Stimulated Conductivity and Luminescence in Polycrystalline Diamond Films

“…This enhancement is called ªprimingº or ªpumpingº, and seems to be due to a reversible modification of the charge state of the deep levels. Another example is the photo-enhancement of the photoconductivity which has been observed by Vermeulen and Halperin in diamond crystals [2] and Vaitkus et al [3] in CVD diamond films.…”

Electronic properties of CVD diamond

“…This is due to growth properties of polycrystalline diamond, where crystallites are small at the beginning of the deposition (substrate side) and become larger as the film thickness is increased. Note that the collection efficiency is a function of thermal and optical pre-treatments ('sample priming') as well as of irradiation time of the films as traps and defects get charged during the experiments that causes electric field and recombination variations (for details see [35] and [42]).…”