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Semiconductor Electronics Class 12 Physics | NCERT Chapter 14 | CBSE JEE NEET | One Shot

LearnoHub - Class 11, 12・50 minutes read

Semiconductors are crucial in modern technology, offering a balance between conductors and insulators based on energy levels and impurities, while diodes like LEDs and photodiodes play essential roles in various applications, including solar energy conversion. Solar cells utilize PN junction diodes to convert solar energy into electrical energy efficiently due to their unique operation and can provide current flow without taking it from the circuit.

Insights

  • Semiconductors are crucial components in various electronic devices, possessing properties that bridge the gap between conductors and insulators, impacting their ability to control the flow of electricity effectively.
  • The manipulation of energy levels, impurities, and the formation of p-n junctions in semiconductors play key roles in enhancing their conductivity, allowing for the creation of efficient devices like diodes, rectifiers, and solar cells that are vital in modern technology.

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Recent questions

  • What role do semiconductors play in modern technology?

    Semiconductors control electricity flow in various devices.

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Summary

00:00

Semiconductors: Balancing Conductivity and Insulation

  • Semiconductors are integral to modern technology, controlling the flow of electricity in devices like computers, smartphones, LED bulbs, washing machines, TVs, and digital cameras.
  • Semiconductors have intermediate conductivity and resistivity, falling between conductors and insulators in terms of electrical properties.
  • Conductors allow electricity to flow easily due to free electrons, while insulators prevent electricity flow by not allowing current to pass through.
  • Semiconductors, with their intermediate properties, follow the example of the shifty category, offering a balance between conductors and insulators.
  • Energy levels play a crucial role in determining whether a material is a conductor, semiconductor, or insulator.
  • Silicon, a semiconductor, has four electrons in its outermost shell, allowing it to conduct or not conduct electricity based on energy levels.
  • Energy bands form when energy levels overlap, creating a distinction between the balance band and the conduction band.
  • The energy gap between the balance band and the conduction band determines the energy required to move electrons between them, affecting the material's conductivity.
  • Sodium's electronic configuration showcases how valence electrons can be easily removed to create free electrons, impacting the material's conductivity.
  • Insulators, unlike conductors and semiconductors, have a significant energy gap that prevents the easy movement of electrons, leading to low conductivity.

20:46

"Enhancing Semiconductor Conductivity Through Impurities"

  • Option one involves playing an electronic game to become a police failed state.
  • The second option is to remove the electronics, which is challenging without proper preparation.
  • To free electronics from impurities, one must create their own products.
  • Intrinsic semiconductor, also known as pure semiconductor, lacks impurities.
  • Increasing temperature generates electron-hole pairs in semiconductors.
  • Thermal energy provides conductivity in semiconductors.
  • Adding suitable impurities enhances conductivity in semiconductors.
  • Group thirteen or group five impurities are commonly added to semiconductors.
  • Adding impurities like aluminum or phosphorus improves conductivity.
  • Extra electrons in semiconductors can conduct easily with added impurities.

45:49

"Conductors, junctions, and currents in semiconductors"

  • In a conductor, impurities and energy levels affect the balance.
  • Equilibrium conductors have electrons equal to intrinsic carrier concentration.
  • Formation of a p-n junction involves attaching a peg to both sides.
  • Holes and excess electrons are used from behind to maintain balance.
  • Accumulation of holes and electrons leads to a depletion region.
  • Depletion region widens with more accumulation of charges.
  • Positive and negative charges accumulate on either side of the depletion region.
  • Establishment of an electric field due to accumulated charges.
  • Diffusion and depletion currents balance out in a P-N junction.
  • Forward and reverse biasing affect current flow in a diode.

01:11:21

Diodes: Functions and Applications in Electronics

  • The forward resistance of a diode is much lower than the reverse resistance, leading to higher current flow in forward bias.
  • Diodes are used in various applications like rectifiers, light-emitting diodes (LEDs), solar cells, and photodiodes.
  • A rectifier converts alternating current (AC) into direct current (DC) by changing the input.
  • Full wave rectifiers have a more efficient design compared to half wave rectifiers.
  • Photodiodes are specialized diodes that convert light into electrical signals.
  • Photodiodes have a transparent cover that indicates light exposure.
  • Solar cells utilize PN junction diodes to convert solar energy into electrical energy.
  • Solar cells require a large area to capture more solar radiation for increased power generation.
  • Solar cells operate by generating electrons and holes when exposed to light, creating a potential difference that leads to current flow.
  • Solar cells have an open circuit voltage and unique operation where they supply current to the load without taking it from the circuit.
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