Electronic devices

    The device in which the electron flow through the semiconductor

    Application of the electronics


    Classification of components

    Passive and active or electro-mechanic components.

    Active components

    • Diodes, sources, transistor, FET, BJT, thyristor, SCR optoelectronics, battery, and vacuum tubes.
    • Produce the energy
    • Unidirectional
    • Require source for their operation
    • Provides amplification
    • Have controlling action
    • Non-linear in nature

    Passive components

    • Resistor, inductor, capacitor, memristor, networks, transducers, sensors, detectors, antennas, assemblies, and modules
    • Maintain and store the energy
    • Bidirectional
    • There is no requirement of source
    • Do not provide amplification
    • Do not having controlling action
    • Linear in natural

    Classification of materials

    Depending upon the conductivity of materials they are classified as
    1. Insulators
    2. Semiconductor
    3. Conductor


    • Conductivity is zero
    • Insulator has practically no free electrons at ordinary temperature
    • Conduction and valance bands are separated by a wide energy gap
    • Very high resistivity


    • The conductivity of semiconductor lies in between that of conductor and insulator
    • Energy band gap between conduction and valance is small
    • Conductivity increases with increase in temperature
    • Semiconductor have a negative temperature coefficient


    • The conductivity of the conductor is very high
    • Since VB and CB overlap each other therefore energy band gap is almost zero
    • On increasing the temperature conductivity decreases and resistance increases
    • The conductor has a positive temperature coefficient

    Types of semiconductor

    1. Intrinsic or pure or un-doped
    2. Extrinsic or impure or doped – two types n and p-type

    Intrinsic semiconductor

    These are the pure semiconductor in which no impurity atoms are added. These are no free charge carriers so behave like an insulator.

    Extrinsic semiconductor

    These are the impure semi-conductor that are obtained by the mixing of other atoms to the pure semiconductor. This process is known as doping

    Extrinsic semiconductor are two types
    a) p-type
    b) n-type

    P-type semiconductor

    • If a trivalent impurity is added to the pure semiconductor, a p-type semiconductor is formed
    • Trivalent impurity has three valance electrons
    • In a p-type semiconductor, majority charge carriers are holes and minority charges are electrons.

    N-type semiconductor

    • If a Pentavalent impurity is added to the pure semiconductor, the N-type semiconductor is formed.
    • Pentavalent impurity has five valance electrons
    • In an n-type semiconductor, the majority charge carrier is electrons and minority charge carrier are holes

    Electronic components

    FET - Field-effect transistor
    MOSFET – Metal oxide field effect transistor (MOS transistor)
    JFET - Junction field-effect transistor
    IGBT – Insulated gate bipolar transistor
    BJT – Bipolar junction transistor
    SCR – Silicon controlled rectifier
    TRIAC –  Triode for alternating current
    UJT – Unijunction transistor

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