Which diode emits light when forward biased?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Study for the AAMI Certified Associate in Biomedical Technology Exam. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

Multiple Choice

Which diode emits light when forward biased?

Explanation:
Light emission from a diode occurs when a forward-biased p-n junction uses a direct-bandgap semiconductor. In a light-emitting diode, electrons and holes are injected into the active region and recombine, releasing energy as photons. The material’s bandgap sets the photon energy, so the color of the light depends on that bandgap. Other diodes don’t emit light under normal forward bias: a photodiode is meant to detect light, not emit; a Zener diode is used for voltage regulation in reverse bias and isn’t designed to glow; a Schottky diode is a fast-switching metal–semiconductor junction with no light emission. Therefore, the LED is the one that emits light when forward biased.

Light emission from a diode occurs when a forward-biased p-n junction uses a direct-bandgap semiconductor. In a light-emitting diode, electrons and holes are injected into the active region and recombine, releasing energy as photons. The material’s bandgap sets the photon energy, so the color of the light depends on that bandgap. Other diodes don’t emit light under normal forward bias: a photodiode is meant to detect light, not emit; a Zener diode is used for voltage regulation in reverse bias and isn’t designed to glow; a Schottky diode is a fast-switching metal–semiconductor junction with no light emission. Therefore, the LED is the one that emits light when forward biased.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy