Intrinsic Semiconductor vs. Extrinsic Semiconductor: What's the Difference?
Edited by Aimie Carlson || By Harlon Moss || Updated on October 13, 2023
Intrinsic semiconductors are pure & have equal numbers of electrons & holes; extrinsic semiconductors are doped to enhance charge carriers.
Key Differences
Intrinsic semiconductors refer to pure semiconductors without any significant impurity, while extrinsic semiconductors are intentionally doped with impurities to modify their electrical properties. The electrical conductivity of intrinsic semiconductors is solely determined by the crystal structure and temperature, whereas, for extrinsic semiconductors, the added impurity atoms play a crucial role.
In intrinsic semiconductors, the number of free electrons is equal to the number of holes, maintaining an electrical neutral state within the material. Extrinsic semiconductors, on the other hand, can be manipulated to have an excess of either electrons or holes by using different dopants, thereby encouraging either n-type (more electrons) or p-type (more holes) conductivity.
The electrical conductivity of intrinsic semiconductors is highly dependent on the temperature; as temperature rises, more electron-hole pairs are generated, increasing conductivity. In contrast, extrinsic semiconductors, while also being temperature-dependent, showcase a superior and more manageable conductivity due to the additional carriers introduced by doping.
Intrinsic semiconductors often find their use in applications where high purity is essential, such as in certain types of transistors and diodes. Extrinsic semiconductors, with their manipulated electrical properties, are broadly utilized across the semiconductor industry in devices like transistors, integrated circuits, and photodiodes, where controlled and enhanced conductivity is paramount.
Comparison Chart
Purity
Pure with no intentional impurities.
Doped with intentional impurities.
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Charge Carriers
Equal number of electrons and holes.
Electron or hole dominance depending on dopant type.
Temperature Sensitivity
Highly sensitive to temperature changes.
Still sensitive, but improved conductivity over intrinsic.
Conductivity
Lower conductivity compared to extrinsic.
Higher conductivity due to added charge carriers from dopants.
Usage
Used where high purity is necessary.
Widely used in various electronic components and devices.
Intrinsic Semiconductor and Extrinsic Semiconductor Definitions
Intrinsic Semiconductor
An intrinsic semiconductor is inherently pure and undoped.
The intrinsic semiconductor was crucial for the experiment due to its pure characteristics.
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Extrinsic Semiconductor
Extrinsic semiconductors can manipulate electronic properties, making them pivotal in the creation of electronic components.
The transistor, made of extrinsic semiconductor material, was able to amplify the signal.
Intrinsic Semiconductor
Intrinsic semiconductors typically exhibit poor conductivity at low temperatures.
The engineers observed that the intrinsic semiconductor demonstrated minimal conductivity at sub-zero temperatures.
Extrinsic Semiconductor
Extrinsic semiconductors contain an imbalance of electrons and holes, facilitating controlled electrical conductivity.
The extrinsic semiconductor efficiently conducted electricity due to its surplus of electrons.
Intrinsic Semiconductor
The charge carriers in an intrinsic semiconductor are generated only by thermal energy.
As the temperature rose, the intrinsic semiconductor created more electron-hole pairs.
Extrinsic Semiconductor
N-type and P-type semiconductors are subclasses of extrinsic semiconductors, characterized by electron or hole majority, respectively.
The n-type extrinsic semiconductor exhibited more free electrons as charge carriers.
Intrinsic Semiconductor
Intrinsic semiconductors possess an equal number of electrons and holes.
Due to its balanced charge carriers, the intrinsic semiconductor was electrically neutral.
Extrinsic Semiconductor
An extrinsic semiconductor is intentionally infused with impurities to alter its electrical properties.
To create a p-type extrinsic semiconductor, boron was added to the silicon.
Intrinsic Semiconductor
The conductivity of intrinsic semiconductors increases significantly with temperature due to thermally generated carriers.
Utilizing the intrinsic semiconductor's property, the scientists explored its conductivity behavior at elevated temperatures.
Extrinsic Semiconductor
The performance of an extrinsic semiconductor is modifiable by manipulating the type and concentration of dopants.
By tweaking the doping level, the extrinsic semiconductor’s conductivity was optimized for the application.
FAQs
What is an intrinsic semiconductor?
It's a pure semiconductor without intentional impurities, having equal electrons and holes.
What is the significance of doping in extrinsic semiconductors?
Doping introduces additional charge carriers, enhancing the material’s electrical conductivity.
What are n-type and p-type extrinsic semiconductors?
N-type have more electrons; p-type have more holes due to the type of dopant used.
Why are extrinsic semiconductors widely used in electronics?
Their controllable electrical properties make them versatile for various electronic applications.
How are charge carriers in intrinsic semiconductors generated?
Primarily through thermal excitation, creating electron-hole pairs.
Why are intrinsic semiconductors used in high-frequency applications?
Due to their high purity, they can handle high-frequency operations with minimized loss.
Are intrinsic semiconductors useful in practical electronic devices?
Less commonly than extrinsic, but they're used where high purity and minimal electrical noise are needed.
How does temperature affect extrinsic semiconductors?
It influences conductivity but to a lesser, more manageable extent than intrinsic semiconductors.
How does light exposure affect intrinsic semiconductors?
It can generate additional charge carriers, impacting its conductivity and optical properties.
Can an intrinsic semiconductor be converted to extrinsic?
Yes, through the process of doping with specific impurities.
Why is purity crucial for intrinsic semiconductors?
Purity ensures reliable, consistent properties and minimizes unwanted electrical behavior.
Is it possible to create a p-type extrinsic semiconductor using phosphorus?
No, phosphorus doping creates an n-type semiconductor due to the extra electrons it provides.
How is an extrinsic semiconductor created?
By intentionally adding impurities (doping) to an intrinsic semiconductor to modify its properties.
How do intrinsic semiconductors behave at absolute zero temperature?
Theoretically, they would exhibit insulator-like behavior as thermal excitation of carriers would be minimal.
Can a semiconductor be both intrinsic and extrinsic at different regions?
Yes, through selective doping, a semiconductor can have both intrinsic and extrinsic regions, often used in electronic devices.
Why do intrinsic semiconductors have poor conductivity?
Due to the equal number of electrons and holes, which tend to recombine, limiting current flow.
Can extrinsic semiconductors be reverted back to intrinsic?
No, because the doping process alters the original physical properties.
How does doping level affect the performance of extrinsic semiconductors?
Varying doping levels alter conductivity, charge carrier density, and overall performance.
Are all semiconductors naturally intrinsic?
Yes, intrinsic semiconductors are the pure, undoped form of the material.
Are all extrinsic semiconductors silicon-based?
No, other base materials like germanium can be used to create extrinsic semiconductors.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Aimie CarlsonAimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.
