Question:
An $LED$ is constructed from a $pn$ junction based on a certain semi-conducting material whose energy gap is $1.9\, eV$. Then the wavelength of the emitted light is
An $LED$ is constructed from a $pn$ junction based on a certain semi-conducting material whose energy gap is $1.9\, eV$. Then the wavelength of the emitted light is
Updated On: Apr 15, 2024
- $2.9\times10^{-9} m$
- $1.6\times10^{-8} m$
- $6.5\times10^{-7} m$
- $9.1\times10^{-5} m$
Hide Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Given, energy gap
$E_{g}=1.9 \,eV =1.9 \times 1.6 \times 10^{-19}\, V$
We know that, $E_{g}=\frac{hc}{\lambda}$
$\lambda=\frac{hc}{E_{g}}$
Wavelength of the emitted light,
$\lambda=\frac{6.63 \times 10^{-34} \times 3 \times 10^{8}}{1.9 \times 1.6 \times 10^{-19}} $
$\lambda=6.5 \times 10^{-7}\, m$
Was this answer helpful?
0
0
Top Questions on Semiconductor electronics: materials, devices and simple circuits
- The range of electrical conductivity \( \sigma \) and resistivity \( \rho \) for metals, among the following, is:
- KCET - 2025
- Physics
- Semiconductor electronics: materials, devices and simple circuits
- The reverse saturation current (I0) of a silicon diode at 27°C is \( 10^{-6} \) A. What will be the approximate value of I0 at 67°C? (Assume \( I_0 \) doubles for every 10°C rise in temperature)
- MHT CET - 2025
- Physics
- Semiconductor electronics: materials, devices and simple circuits
- In a silicon semiconductor at room temperature, the intrinsic carrier concentration is \( 1.5 \times 10^{16} \, \text{m}^{-3} \). Calculate the energy band gap of the silicon if the intrinsic carrier concentration is given by: \[ n_i = \sqrt{N_c N_v} e^{-E_g / 2kT} \] Where: - \( N_c = 2.8 \times 10^{25} \, \text{m}^{-3} \) is the effective density of states in the conduction band, - \( N_v = 1.04 \times 10^{25} \, \text{m}^{-3} \) is the effective density of states in the valence band, - \( k = 1.38 \times 10^{-23} \, \text{J/K} \) is the Boltzmann constant, - \( T = 300 \, \text{K} \) is the temperature.
- MHT CET - 2025
- Physics
- Semiconductor electronics: materials, devices and simple circuits
- In a p-n junction diode, what happens to the width of the depletion region when the forward bias is increased?
- MHT CET - 2025
- Physics
- Semiconductor electronics: materials, devices and simple circuits
- Given below are two statements: Statement-I: The equivalent emf of two nonideal batteries connected in parallel is smaller than either of the two emfs. Statement-II: The equivalent internal resistance of two nonideal batteries connected in parallel is smaller than the internal resistance of either of the two batteries. In light of the above statements, choose the correct answer from the options given below.
- JEE Main - 2025
- Physics
- Semiconductor electronics: materials, devices and simple circuits
View More Questions
Questions Asked in KCET exam
- If the number of terms in the binomial expansion of \((2x + 3)^n\) is 22, then the value of \(n\) is:
- KCET - 2025
- Binomial theorem
The circuit shown in the figure contains two ideal diodes \( D_1 \) and \( D_2 \). If a cell of emf 3V and negligible internal resistance is connected as shown, then the current through \( 70 \, \Omega \) resistance (in amperes) is:
- KCET - 2025
- Refractive index
Charges are uniformly spread on the surface of a conducting sphere. The electric field from the center of the sphere in a point outside the sphere varies with distance \( r \) from the center as
- KCET - 2025
- Electric Dipole
- Choose the correct statement from the following:
- KCET - 2025
- evolution and natural selection
- Darwin’s finches represent one of the best examples of ____
- KCET - 2025
- evolution and natural selection
View More Questions
Concepts Used:
Semiconductors
Semiconductors are a crystalline solid materials, whose electrical conductivity lies between a conductor and an insulator. Semiconductors are mainly used in the manufacturing of electronic devices like capacitors, transistors, diodes, Integrated circuits, etc.
Properties of Semiconductor:
- Semiconductor acts like an insulator at Zero Kelvin. On increasing the temperature, it works as a conductor.
- Due to their exceptional electrical properties, semiconductors can be modified by doping to make semiconductor devices suitable for energy conversion, switches, and amplifiers.
- Lesser power losses.
Uses of Semiconductor:
- Semiconductors are widely used in manufacturing electronics devices like transistors, diodes, sensors, integrated circuits.
- Semiconductors are widely used in all electronic devices, like mobile phones, digital cameras, communication devices, trains, ATMs, etc.