The I-V characteristic of an text{LED} is : | vedclass

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(A) An $	ext{LED}$ (Light Emitting Diode) operates under forward bias conditions and emits light when energized.According to the energy band theory,t

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(A) An $	ext{LED}$ (Light Emitting Diode) operates under forward bias conditions and emits light when energized.According to the energy band theory,the energy of the emitted photon is given by $E = h
u = \frac{hc}{\lambda} \approx E_g$,where $E_g$ is the band gap energy of the semiconductor material.Since the frequency $
u$ (or energy) of the emitted light is directly proportional to the band gap energy $E_g$,and the threshold voltage (potential barrier) $V_k$ is also directly related to the band gap energy $(V_k \approx E_g/e)$,it follows that light with a higher frequency requires a higher threshold voltage.Comparing the frequencies of the colors: $
u_{	ext{blue}} > 
u_{	ext{green}} > 
u_{	ext{yellow}} > 
u_{	ext{red}}$.Therefore,the threshold voltage required for emission follows the order: $V_{	ext{blue}} > V_{	ext{green}} > V_{	ext{yellow}} > V_{	ext{red}}$.This corresponds to the $I-V$ characteristic curves where the blue light curve is shifted furthest to the right along the voltage axis.

The $I-V$ characteristic of an $\text{LED}$ is $:$

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