Discuss the similarity and difference between a light emitti

Discuss the similarity and difference between a light emitting diode (LED) and a photovoltaic solar cell. (50~100 words)

Solution

similarities

1. both made up of semiconductor material. led(GaAS, InP) solarcell(GaAs,Si).

2 both has pn junction formation.

3. both are direct energy conversion devices.

4 IN CASE OF LED Wavelenth of light (output of LED) depends on energy band gap of semiconductor material, in solar cell output voltage depends on energy band gap.Thus we can say in both device output is function of energy band gap.

DIFFERENCES

1. LED takes elctrical as input and produces light as outpu whereas solarcell take light as input and produce electrical energy as output.

2. In case of LED light is produced by recombination whereas in case of solar cell EMF is induced by charge seperation mechanism.

3. In LED mainly direct band gap semiconductor is used whereas In pv solar cell both direct and indirect semiconductor are used todat silicon solar cell is mainly used which is indirect semiconductor.

4 I-V characterstics of LED Is in first quardinate whereas I-V Characterstics of solar cell is in fourth quardinate. ABOVE point repesent LED is power consuming device whereas solar cell is power producin device.

5. in LED current flows from P to N type semiconductor & in solar cell current flows from N to P type solar cell.