Photo-electromotive-force effect in semiconductors

Observation of fluid flow changes at low velocities interval by adaptive photodetection

“…(2) with average radiant intensity , fringe pattern contrast (3) and spatial frequency (4) the expression of generated P-EMF current density for a monopolar semiconductor [4,5,9] with small contrast , no external DC field applied, no saturation of impurity centres and a running interference pattern speed is:…”

“…Recently, adaptive photodetection, a relatively new optoelectronic method have been used as an alternative technique for several applications as remote measurement of surface vibrations, analysis of modulated optical signal power spectrum, phase-locking of separated lasers, or characterization of photonic parameters related to photoconductive materials [4]. An adaptive photodetector is a device based on the photo-electromotive force effect (P-EMF), which consists on the appearance of an alternating current in a photoconductive material, a semiconductor crystal for example, illuminated by a regular (interference) or irregular (speckle) oscillating optical pattern of varying intensity [5].…”

Non-steady-state photoelectromotive force induced by a vibrating Ronchi grating: manifestation of a fractal structure

“…For an intensity distribution Ix the amplitude of the photoEMF current for vibration amplitude of the illuminating pattern δ at a distance z is approximately given by [9,12] Jδ…”

“…The photoEMF is a technique based on the properties of highly resistive photoconductors, which produce an electric current when they are illuminated with a moving (vibrating) pattern of light [8,9]. The photoEMF effect has been extensively used for the determination of photoconductor properties such as the photocarrier sign and diffusion length [10].…”

Influence of a Time-Dependent Applied Electric Field on the Photocurrent in Photorefractive Materials

“…This nonstationary photocurrent can be considered as the alternative optical technique for the study of the space charge grating formation in semiconductors. The presence of an external alternating electric field on the photo-EMF effect is quite useful for characterization of hybrid materials [7,8].…”