What is the most commonly used semiconductor material?
Analysis & Theory
Silicon is the most widely used semiconductor material due to its abundance and suitable electrical properties.
Which element is commonly used in LEDs and laser diodes along with arsenic?
Analysis & Theory
Gallium arsenide (GaAs) is a compound semiconductor used in high-speed and optoelectronic applications like LEDs.
Which of the following is a property of intrinsic semiconductors?
A
Contain many free electrons
B
Contain added impurities
C
Are pure semiconductors
D
Have no conduction ability
Analysis & Theory
Intrinsic semiconductors are pure materials like silicon or germanium without any added impurities.
What happens when a pentavalent impurity is added to silicon?
A
Creates a p-type semiconductor
C
Creates an n-type semiconductor
Analysis & Theory
Pentavalent impurities (like phosphorus) add free electrons, forming n-type semiconductors.
Which of the following is a trivalent impurity used in semiconductors?
Analysis & Theory
Boron is a trivalent element that creates holes in the crystal structure, forming p-type semiconductors.
What is the role of doping in semiconductors?
B
To increase energy loss
C
To increase conductivity
D
To convert heat to electricity
Analysis & Theory
Doping adds impurities to increase the number of free charge carriers, improving conductivity.
Which semiconductor material has higher electron mobility than silicon?
Analysis & Theory
Gallium arsenide has higher electron mobility, making it suitable for high-frequency applications.
Which of the following is an example of an intrinsic semiconductor?
B
Silicon with phosphorus
Analysis & Theory
Pure germanium without any impurities is an intrinsic semiconductor.
What is the typical band gap of silicon at room temperature?
Analysis & Theory
Silicon has a band gap of approximately 1.1 eV, which allows for effective control of conductivity.
Which of the following best describes a semiconductor?
B
A material with no charge carriers
C
A material whose conductivity lies between a conductor and an insulator
Analysis & Theory
Semiconductors have electrical conductivity between that of conductors and insulators, which can be controlled via doping.