Question 118: Semiconductors and Logic Gates

Question

LED is constructed from Ga-As-P semiconducting material. The energy gap of this LED is 1.9 eV. Calculate the wavelength of light emitted and its colour.
[h = 6.63 $$	imes$$ 10
$$-$$34
Js and c = 3 $$	imes$$ 10
8
ms
$$-$$1
]

Accepted Answer

We know that $$E = {{hc} \over \lambda }$$
$$\lambda  = {{hc} \over E} \Rightarrow {{1240(in\,eV)} \over {E(in\,eV)}}$$
$$\lambda  = {{1240} \over {1.9}}$$
= 652.63 nm $$ \approx $$ 654 nm
Wavelength of red light is 620 nm to 750 nm

Answer

654 nm and orange colour

Answer

654 nm and red colour

Answer

1046 nm and red colour

Answer

1046 nm and blue colour

Semiconductors and Logic Gates

LED is constructed from Ga-As-P semiconducting material. The energy gap of this LED is 1.9 eV. Calculate the wavelength of light emitted and its colour. [h = 6.63 $\times 10 -34 Js and c = 3 \times 10 8 ms -$1 ]

Choose the correct answer: