Which of the following is/are the characteristic(s) of direct band gap semiconductor Ga-As?
(A) Less sharp absorption band (B) Large values of extinction coefficient
Choose the correct answer from the options given below:

Correct option is B

Explanation Gallium Arsenide (Ga-As) is a direct band gap semiconductor characterized by its ability to efficiently absorb and emit light. One of the main characteristics of Ga-As is its large values of extinction coefficient, which indicates its strong absorption capabilities at certain wavelengths. However, the statement about less sharp absorption bands is misleading in the context of Ga-As, as direct band gap materials typically have well-defined and sharper absorption edges due to the direct transitions between the valence and conduction bands.
Information Booster
· Direct Band Gap: Ga-As allows for direct electronic transitions, making it effective for light emission and absorption.
· Extinction Coefficient: A larger extinction coefficient indicates more efficient absorption of photons, which is crucial for optoelectronic devices like lasers and LEDs.
· Applications: Ga-As is widely used in high-efficiency solar cells, laser diodes, and photodetectors.
Additional Information
· Absorption Bands: Direct band gap semiconductors tend to have sharper absorption edges compared to indirect band gap semiconductors.
· Comparison with Silicon: Unlike silicon (an indirect band gap semiconductor), Ga-As's direct band gap facilitates efficient light interaction, making it superior in optoelectronic applications.