An LED is constructed from a p-n junction based on a certain Ga-As -P semiconducting material whose energy gap is 1.9 eV. What is the wavelength (in nm) of the emitted light?

Question

An LED is constructed from a p-n junction based on a certain Ga-As -P semiconducting material whose energy gap is 1.9 eV. What is the wavelength (in nm) of the emitted light? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

If λ is the wavelength of emitted light, then Eg = (hc/λ) or λ = (hc/Eg) = ((6.63 × 10-34) × ( 3 × 108)/(1.9) × (1.60 × 10-19)) = 6.5 × 10-7 m = 650 nm

Q. An LED is constructed from a $p - n$ junction based on a certain $G a - A s - P$ semiconducting material whose energy gap is $1.9 e V$ . What is the wavelength (in nm) of the emitted light?

If $λ$ is the wavelength of emitted light, then
$E_{g} = \frac{h c}{λ}$
or $λ = \frac{h c}{E _{g}}$
$= \frac{( 6.63 \times 1 0 ^{- 34} ) \times ( 3 \times 1 0 ^{8} )}{( 1.9 ) \times ( 1.60 \times 1 0 ^{- 19} )}$
$= 6.5 \times 1 0^{- 7} m = 650 nm$

Q. An LED is constructed from a p−n junction based on a certain Ga−As−P semiconducting material whose energy gap is 1.9eV. What is the wavelength (in nm) of the emitted light?

If λ is the wavelength of emitted light, then Eg​=λhc​ or λ=Eg​hc​ =(1.9)×(1.60×10−19)(6.63×10−34)×(3×108)​ =6.5×10−7m=650nm

Q. An LED is constructed from a $p - n$ junction based on a certain $G a - A s - P$ semiconducting material whose energy gap is $1.9 e V$ . What is the wavelength (in nm) of the emitted light?

If $λ$ is the wavelength of emitted light, then
$E_{g} = \frac{h c}{λ}$
or $λ = \frac{h c}{E _{g}}$
$= \frac{( 6.63 \times 1 0 ^{- 34} ) \times ( 3 \times 1 0 ^{8} )}{( 1.9 ) \times ( 1.60 \times 1 0 ^{- 19} )}$
$= 6.5 \times 1 0^{- 7} m = 650 nm$