摘要:
A laser made of a stack of laser diodes. The stack is inserted between two mirrors to create a laser cavity. The stack of diodes is produced by epitaxial growth of a set of semiconductor layers. The ohmic contact between two adjacent laser diodes is provided by an Esaki diode junction. The optical field of the mode created in the laser cavity is periodically cancelled at the Esaki diode junctions so as to create structures with small dimensions.
摘要:
In an array R of field-effect transistors for detecting analytes, each transistor of the array comprises a gate G, a semiconductor nanotube or nanowire element NT connected at one end to a source electrode S and at another end to a drain electrode D, in order to form, at each end, a junction J1, J2 with the channel. At least transistors FET1,1, FET1,2 of the array are differentiated by a different conducting material (m1, m2) of the source electrode S and/or drain electrode D.
摘要:
The quantum well semiconductor laser has at least one ultrafine layer with a thickness smaller than the critical thickness, the material of which is isoelectronic with that of the well.
摘要:
A multiple quantum well light emitting compositional semiconductor device ch as a laser diode or a light emitting diode has an active region comprising an alternating sequence of layers of well layer material and of barrier layer material. The thickness of the barrier layer and of the adjacent well layers is chosen such that for one type of charge carrier a relatively high probability exists for such charge carriers to be present in the barrier region whereas the other type of charge carriers are localized in the potential wells. In this way it is possible to reduce the probability of non-radiative Auger recombination processes occurring thus reducing the threshold current and increasing the quantum efficiency of the device. This is particularly important since material systems with a small bandgap which lase at long wavelengths suitable for optical fibre transmission normally suffer performance penalties due to non-radiative Auger recombination and these penalties can be substantially reduced by tailoring the layer thicknesses to achieve the described probability distributions.
摘要:
In an array R of field-effect transistors for detecting analytes, each transistor of the array comprises a gate G, a semiconductor nanotube or nanowire element NT connected at one end to a source electrode S and at another end to a drain electrode D, in order to form, at each end, a junction J1, J2 with the channel. At least transistors FET1,1, FET1,2 of the array are differentiated by a different conducting material (m1, m2) of the source electrode S and/or drain electrode D.
摘要:
A semi-conducting structure delimits two quantal wells (CP1, CP2) connected across a barrier layer (CB). The application of an electric field to the structure makes possible the transfer of electrons from one of the wells to the other. The electron-hole pairs are created by a wave-pump, or by the doping of one of the wells. This makes possible, in particular, a dual control by means of the wave-pump and the electric field, thus creating an "AND"-function modulator.