Understanding the Mechanics of Light-Induced Voltage in L.E.D.s

In summary: LED as the electrons make their transitions.Does ur explanation allow for this - do u mean that the electrons released would move to the holes in the p type material.I don't see anything wrong with my explanation.
  • #36
ryan750 said:
so the light provides the energy to valence electrons in the n type to be excited and they are attracted to the p type and combine with holes. This process carried out produces energy changes to the electrons and holes which creates the potential difference seen.

is this right?

Er.. no!

First of all, you need to understand PN junction! This is INDEPENDENT of LED and the photodiode condition that you asked at the beginning of this thread. You are now mixing the physics of PN junction with the physics of that question you asked AND the emission of light in LEDs. It has gotten utterly confusing.

The depletion zone (and the build up of internal E-field) occurs simply because the p-type and n-type semiconductors are in contact with each other. Whether you are going to use this for LED's, or photodiode, is irrelevant.

In the photodiode, the electron that migrates does NOT recombine with the hole! If it does, this is creates light and thus, the LED situation. This is not what you're asking for and it is why I said you're mixing different stuff into one scenario.

I don't want to cut-and-paste what I have said earlier, but I'm going to:

1. In the P-type semiconductor, an electron is excited from the valence band into the conduction band, leaving behind a positive hole in the valence band. If this is close to the depletion zone, it sees an electric field that will force it into the N-type semiconductor (similar to a forward bias). The hole, on the other hand, stays in the P-type. As more of these occur, there will be an additional accumulation of holes in the P-type and more electrons in the N-type.

2. In the N-type semiconductor, the same excitation occurs, but this time, it is the holes that see an E-field that will cause it to migrate over to the P-type. The electrons stay in the N-type.

The combination of 1 and 2 will force the accumulation of a potential bias (similar to a forward bias) between the P and N-type semiconductors. It is only sustainable with continued light source. If you cut the light source, the equilibrium is destroyed.

Notice that I said nothing about any recombination of electrons and holes. Such process is the source of light in LED's and that's not what I was describing! Instead, it is the accumulation of charges on each side of the PN junction that is the source of the potential difference that you detected.

Zz.
 
<h2>What is the mechanism behind light-induced voltage in L.E.D.s?</h2><p>The mechanism behind light-induced voltage in L.E.D.s is known as the photovoltaic effect. This effect occurs when photons of light interact with the semiconductor material in the L.E.D., causing the release of electrons and the generation of a voltage difference.</p><h2>How does the structure of an L.E.D. contribute to its light-induced voltage?</h2><p>The structure of an L.E.D. plays a crucial role in its light-induced voltage. The semiconductor layers within the L.E.D. are designed to have a specific bandgap, which allows for the efficient conversion of light energy into electrical energy. Additionally, the p-n junction within the L.E.D. helps to create a built-in electric field that aids in the separation of electrons and holes, further contributing to the voltage generation.</p><h2>What factors affect the magnitude of light-induced voltage in L.E.D.s?</h2><p>The magnitude of light-induced voltage in L.E.D.s can be affected by several factors, such as the intensity and wavelength of the incident light, the material and structure of the L.E.D., and the temperature of the device. Higher light intensity, shorter wavelengths, and lower temperatures typically result in a higher voltage output.</p><h2>Can light-induced voltage in L.E.D.s be used for practical applications?</h2><p>Yes, light-induced voltage in L.E.D.s has several practical applications, such as in solar cells, photodetectors, and optoelectronic devices. These devices utilize the photovoltaic effect of L.E.D.s to convert light energy into electrical energy, making them highly efficient and sustainable sources of power.</p><h2>Are there any challenges in understanding the mechanics of light-induced voltage in L.E.D.s?</h2><p>While the basic principles behind light-induced voltage in L.E.D.s are well understood, there are still ongoing research and developments to improve the efficiency and performance of these devices. Additionally, the complex interactions between light, materials, and electric fields make it a challenging area of study, requiring advanced techniques and equipment for accurate measurements and analysis.</p>

Related to Understanding the Mechanics of Light-Induced Voltage in L.E.D.s

What is the mechanism behind light-induced voltage in L.E.D.s?

The mechanism behind light-induced voltage in L.E.D.s is known as the photovoltaic effect. This effect occurs when photons of light interact with the semiconductor material in the L.E.D., causing the release of electrons and the generation of a voltage difference.

How does the structure of an L.E.D. contribute to its light-induced voltage?

The structure of an L.E.D. plays a crucial role in its light-induced voltage. The semiconductor layers within the L.E.D. are designed to have a specific bandgap, which allows for the efficient conversion of light energy into electrical energy. Additionally, the p-n junction within the L.E.D. helps to create a built-in electric field that aids in the separation of electrons and holes, further contributing to the voltage generation.

What factors affect the magnitude of light-induced voltage in L.E.D.s?

The magnitude of light-induced voltage in L.E.D.s can be affected by several factors, such as the intensity and wavelength of the incident light, the material and structure of the L.E.D., and the temperature of the device. Higher light intensity, shorter wavelengths, and lower temperatures typically result in a higher voltage output.

Can light-induced voltage in L.E.D.s be used for practical applications?

Yes, light-induced voltage in L.E.D.s has several practical applications, such as in solar cells, photodetectors, and optoelectronic devices. These devices utilize the photovoltaic effect of L.E.D.s to convert light energy into electrical energy, making them highly efficient and sustainable sources of power.

Are there any challenges in understanding the mechanics of light-induced voltage in L.E.D.s?

While the basic principles behind light-induced voltage in L.E.D.s are well understood, there are still ongoing research and developments to improve the efficiency and performance of these devices. Additionally, the complex interactions between light, materials, and electric fields make it a challenging area of study, requiring advanced techniques and equipment for accurate measurements and analysis.

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