'p' and 'n' type semi conductor

P-type and N-type Semiconductors

Semiconductors possess electrical conductivity that lies between the high conductivity of conductors and the low conductivity of insulators. By introducing impurities through a process known as doping, we can significantly enhance their conductivity. Based on the type of impurity added, doped semiconductors are categorized as P-type or N-type.

Intrinsic vs. Extrinsic Semiconductors

An intrinsic semiconductor is a pure semiconductor without any significant dopants—examples include silicon (Si) and germanium (Ge). When dopants are added, they become extrinsic semiconductors and are classified as either P-type or N-type.

N-type Semiconductor

An N-type semiconductor is created by doping a pure semiconductor with elements that have five valence electrons (pentavalent), such as phosphorus (P), arsenic (As), or antimony (Sb). These dopants provide an extra electron that becomes available for conduction.

• Majority carriers: Electrons
• Minority carriers: Holes
• Result: Improved conductivity due to the availability of free electrons

P-type Semiconductor

A P-type semiconductor is formed by doping a pure semiconductor with elements having three valence electrons (trivalent), such as boron (B), aluminum (Al), or gallium (Ga). These create a deficiency of electrons, known as holes, which act as positive charge carriers.

• Majority carriers: Holes
• Minority carriers: Electrons
• Result: Conduction occurs as electrons move to fill holes, creating apparent positive charge movement

Key Differences Between P-type and N-type Semiconductors

Applications

• P-N junction diodes
• Transistors (BJT and FET)
• Solar cells
• Integrated circuits

Understanding the difference between P-type and N-type semiconductors is crucial in electronics and solid-state physics, as they form the building blocks of most modern electronic devices.