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Ibn al-Haytham and the International Year of Light: His Legacy
Published in Azzedine Boudrioua, Roshdi Rashed, Vasudevan Lakshminarayanan, Light-Based Science: Technology and Sustainable Development, 2017
A p–n diode is a device made out of two semiconductor materials. One part, referred to as the n-type, is characterised by being rich in electrons, while the other type is characterised as being rich in holes, referred to as p-type material (note that a hole is essentially an electron vacancy). In the most widely used p–n diodes, the materials used are made out of silicon which starts with an equal amount of electrons and holes. To convert it to an active device, a minute amount of another material rich in electrons or holes is added to convert it to either an n- or p-type material. When these two different type of materials are brought into contact with each other, electrons and holes combine (i.e., an electron fills in a hole vacancy) and give out some energy that can be captured in the form of light. In this case, the diode is referred to as a light-emitting diode (LED). This emitted LED light has not always been the sought after sun resembling ‘white light’ as it comes in different colours depending on the materials used. It was proposed that if a number of different LED coloured lights, red, green and blue, could be produced, then when these are combined, they would yield a white light. Red and green LEDs have been developed for over 50 years, but the missing colour, the blue LED needed to produce the promised sun resembling ‘white light’, has eluded researchers for many years.
Lighting and Communications: Devices and Systems
Published in Zabih Ghassemlooy, Luis Nero Alves, Stanislav Zvánovec, Mohammad-Ali Khalighi, Visible Light Communications, 2017
Luis Nero Alves, Luis Rodrigues, José Luis Cura
It is possible to improve the performance of the optical detection process using P–N junctions. As mentioned before, the photon-generated current depends on the existence of an external field. A semiconductor sample of a given type behaves generally as a resistive material. Thus, under the action of external electric field, the current through the sample is not only due to photogenerated carriers. One possibility to avoid this behavior is to rely on P–N junction diodes. In a reversed biased P–N diode, there is a strong electric field applied to the depletion region near the junction. This field can remove any minority carriers generated within this region. The current passing through the device is very small. If the depletion region is exposed to external radiation, carriers can be generated by the process previously described. These carriers are then removed from this region by the reverse electric field, giving rise to a photogenerated current, free from other effects. The current–voltage characteristic of a photodiode combines two contributions: the behavior of a normal junction diode, given by (2.24), and the photogenerated current given by (2.38). The end result is given by:
Solar supplied two-output DC–DC converters in the application of low power
Published in Automatika, 2021
An ideal PV cell contains a sunlight-generated source of current and is called an Iph. Solar irradiance amount has an effect on Iph's value. A P-N diode is a parallel connection to the current source and the final current at the terminal of the circuit displayed as “I”. It is the distinction between the photon current and the current flowing through the diode. V is the terminal voltage of the circuit.
A dynamic model of power metal-oxide-semiconductor field-effect transistor half-bridges for the fast simulation of switching induced electromagnetic emissions
Published in Mathematical and Computer Modelling of Dynamical Systems, 2019
D. Büchl, W. Kemmetmüller, T. Glück, B. Deutschmann, A. Kugi
A characteristic feature of minority-carrier devices (like the parasitic p-n diode) is the diffusion of charge carriers into the neutral region of the p-n junction when the diode conducts. This stored diffusion charge in the neutral region depends on the diode current and is given by
A Water Cycle Approach for Maximum Power Point Tracking through an Interleaved Boost Converter
Published in Electric Power Components and Systems, 2023
K. Krishnaram, T. Suresh Padmanabhan
It is possible to determine the mathematical model of a PV cell based on a P-N diode. It is made up of an expression representing internal occurrences and the inclusion of the PV's current (that is proportionate to sunlight). Figure 2 depicts the equivalent electrical network.