Question

a particular deep blue commercial led emits an optical power of 453 mw at 455 nm when the current is 350 ma and the forward voltage is 3.2 v. what are the power conversion efficiency, and external quantum efficiency? b a particular green led based on ingan mqw active region emits at a wavelength of 528 nm. at an led current of 350 ma, the forward voltage is 3.2 v. the emitted luminous flux is 93 lm. what are the power conversion efficiency, external quantum efficiency, and the emitted optical power (radiant flux)? c a particular red led emits 320 mw of optical power at 657 nm when the current is 400 ma and the forward voltage is 2.15 v. what are the power conversion efficiency and external quantum efficiency?

Answer 1

LEDs emit light in the visible spectrum. The power conversion efficiency and external quantum efficiency depend on the luminous flux, electrical power input, and luminous efficacy. Blue, green, and red LEDs have different efficiency values.

LEDs (Light Emitting Diodes) are widely used for commercial and residential lighting. They emit light in the visible spectrum and their color depends on the materials used in the semiconductor and the current.

To calculate the power conversion efficiency, we divide the luminous flux by the electrical power input. The external quantum efficiency is the ratio of the emitted optical power to the electrical power input. To calculate the emitted optical power, we divide the luminous flux by the luminous efficacy.

In case of the blue LED, the power conversion efficiency is 43.5% and the external quantum efficiency is 48.5%.

In case of the green LED, the power conversion efficiency is 46.5%, the external quantum efficiency is 49.5%, and the emitted optical power is 279.6 mW.

In case of the red LED, the power conversion efficiency is 20.1% and the external quantum efficiency is 35.6%.