Difference Between Intrinsic Semiconductor and Extrinsic Semiconductor
Last Updated : 11 Sep, 2023
Semiconductors are unique materials that possess moderate conductivity, falling between conductors and insulators. The conductivity of semiconductors proves incredibly advantageous for various applications. When we add energy to semiconductors, like heat or light, it makes some particles move around. This creates empty spots that act like positive charges known as holes. This lets electrons move and electricity flow. Transistors, integrated circuits, and diodes are made from semiconductors, which are useful. They can also be switches, amplifiers, and memory cells. They're like the important parts that make computers, phones, and many other cool things that have changed our world.
Intrinsic Semiconductor
Intrinsic Semiconductors are pure semiconductors like silicon, germanium, and carbon. They do not have contaminations therefore they do not carry a lot of charge. This scarcity of charge carriers bestows intrinsic semiconductors with distinct characteristics:
- Electron-Hole Pairs: In intrinsic semiconductors, heat can make pairs of electrons and holes. This happens when an electron moves from one part to another, leaving behind a positively charged hole.
- Limited Conductivity: Intrinsic semiconductors don't conduct electricity well because they have few charge carriers, which means they're not great for everyday electronics.
- Temperature Dependence: As temperature rises, more electron-hole pairs are generated, and conductivity increases.
- Photovoltaic Applications: Intrinsic semiconductors are used in photovoltaic devices like solar panels. When light hits them, they make electricity by creating electron-hole pairs.
Extrinsic Semiconductors
Extrinsic semiconductors are the type of semiconductor which are doped with impurities. They are intentionally modified to have different electrical properties. Doping introduces extra electrons or electron-deficient areas called holes, which influence how well the material conducts electricity and help regulate the flow of current in electronic circuits.
Doping in Extrinsic Semiconductors
Doping means adding impurities on purpose to change how a semiconductor works. In extrinsic semiconductors, two types of impurities are commonly added through the process of doping:
N-Type doping: Donor impurities, such as phosphorus or arsenic, are added to increase the concentration of electrons, leading to enhanced conductivity
P-Type doping: Acceptors like boron or gallium are used as impurities, which make gaps in the material. This boosts the number of charge carriers and changes how they conduct electricity.
Types of Extrinsic Semiconductors Based on Doping:
1. N-Type Semiconductors: In N-Type Semiconductors some elements are added from Group 15 of the periodic table, like phosphorus or arsenic. Because these impurities have more valence electrons than the atoms in the semiconductor crystal, they introduce extra electrons into the crystal structure. These extra electrons become the majority charge carriers, significantly enhancing the material's conductivity.
2. P-Type Semiconductors: In P-type semiconductors, elements are added from Group 13 of the periodic table, like boron or gallium to make holes in the material. These elements have fewer valence electrons than the atoms in the semiconductor crystal. As a result, they create "holes" in the crystal structure where electrons are missing. These holes become the majority of charge carriers in P-type materials.
Difference Between Intrinsic and Extrinsic Semiconductors
|
Low impurity content | Higher impurity content |
No intentional impurities | Donor and acceptor impurities. |
Few available charge carriers | Abundant charge carriers |
Poor conductivity | Enhanced conductivity |
Single type (pure) | N-type and P-type (doped) |
Electrons and holes | Electrons (N-type) and holes (P-type) |
Low carrier density | High carrier density |
High-temperature sensitivity | Moderate to low temperature sensitivity |
Relies on light for carrier generation | Enhanced carrier generation |
Limited role in complex circuits | Essential for active electronic devices |
Better thermal stability | Varied thermal stability |
Less efficient energy consumption | More efficient energy consumption |
Examples: Solar panels, photodetectors, sensors, thermoelectric generators | Examples: Transistors, diodes, amplifiers, light emitting diodes |
Conclusion
In conclusion, the differences between intrinsic and extrinsic semiconductors show us how nature and innovation work together. Intrinsic ones are like natural talents, they're great for solar energy and special tasks. Extrinsic semiconductors, with some changes, become the superheroes of our electronic devices.
This combination of natural strengths and human-made enhancements shapes how we use technology. These semiconductors are like the stars of technology. They help us catch sunlight and make gadgets work.