WebAug 1, 2007 · Here, E pD is the THz field amplitude due to the photo-Dember effect, a and b are constants depending on the third-order nonlinear susceptibility and other material parameters, and E s is the surface electrical field strength. Most probable cause of this field is the Fermi-level pinning at some energy level in the middle of the band gap of Ge. When … WebMay 6, 2024 · The photo-Dember effect is the transient current caused by the difference between the mobility or diffusion constants of electrons and holes. When the laser pulses excite the sample, photogenerated electrons and holes are localized near the interface and share the center of mass. Because electrons and holes diffuse away from the interface at ...
Lasers
WebJun 10, 2015 · The photo-Dember effect arises from the asymmetric diffusivity of photoexcited electrons and holes, which creates a transient spatial charge distribution and hence the buildup of a voltage. Conventionally, a strong photo-Dember effect is only observed in semiconductors with a large asymmetry between … WebAug 12, 2008 · A theoretical investigation of the photovoltage produced in insulated CdS‐type crystals excited by strongly absorbed radiation has been carried out, taking into account trapped electrons and trapped holes in addition to free electrons. Expressions for the photovoltage dependence on intensity for isolated crystals have been obtained over a ... phosphate hopper
Photoelectric effect - Wikipedia
WebJun 8, 2024 · In semiconductor physics, the photo–Dember effect (named after its discoverer Harry Dember) is the formation of a charge dipole in the vicinity of a … WebSep 9, 2015 · The photo-Dember effect is dominant for a narrow band gap semiconductor such as InAs; however, THz emission from the surfaces of semiconductors with wider band gaps such as GaAs and InP originates ... In semiconductor physics, the photo–Dember effect (named after its discoverer Harry Dember ) is the formation of a charge dipole in the vicinity of a semiconductor surface after ultra-fast photo-generation of charge carriers. The dipole forms owing to the difference of mobilities (or diffusion constants) for holes and electrons which combined with the break of symmetry provided by the surface lead to an effective charge separation in the direction perpendicular to the surface. In a… phosphate hill weather