Electrophotographic discharge of CdS explained by a surface-depletion discharge model

Abstract

We report on a new model which explains the dark decay of the surface potential of a charged thin-film photoconductor on a grounded substrate. The model, called here the surface-depletion discharge model, has been developed to explain the dark discharge of cadmium sulfide films with thicknesses varying from 0.17 to 1.59 μm. The model is also applicable to thin hydrogenated amorphous silicon carbide films. During the discharge the bulk charge density remains constant. However, a fundamental change occurs in the discharge of a film with thickness L when at the depletion time td the surface charge density σ(td) is counterbalanced by the bulk charge density ρ(td), thus, σ(td)=ρ(td)L. From that moment onward, the bottom of the bulk charge region shifts to the surface of the photoconductor. In the model proposed here, the discharge is governed by surface charge injection. In addition, we show that the bulk space charge depends on the surface charge deposited by corona charging. Furthermore, the dark discharge rate is found to increase if the amount of surface charge deposited increases.

Extracting the optical parameters of thermally evaporated Se film by modelling of transmittance spectra: Effect of heat treatment

“…Among several compositions and alloys of chalcogens, the modest form is the pure elements, selenium for example. Pure selenium films and its alloys create a centre of consideration due to its numerous applications such as memory appliances, electrophotography and switching [1][2][3][4][5][6][7]. Nowadays, Se film is used as a photoconductor in HARPICON camera for high-sensitivity TV, x-ray sensitive vidicons (X-icon), electro-photographic (Xerography) and IR fibre optics and as a Videocon photoconductor material [8][9][10][11].…”

Optoelectronic properties of new amorphous silicon photoreceptor

“…Furthermore, we will investigate the effects of photoreceptor with a-C:H passivation layer. 5 have a sufficient surface trap density to trap the ion charge. Then, it must have an effective blocking substrate electrode.…”