Diodes and electromagnetic emmission Help?

In summary, creating a desired electromagnetic wavelength for a diode's pn junction is not a straightforward process. There is no accurate formula for determining the correct dopant and concentration. Instead, the industry relies on data from thousands of experiments and tables to select the appropriate dopant for the desired LED color. However, this information may be outdated and there are some resources available for basic LED color tables.
  • #1
radaballer
86
0
How would one go about figuring out what to dope a diodes pn junction with in order to create a desired electromagnetic wavelength ?
 
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  • #2
You don't. My solid state professor told me that no one ever came up with an accurate model for this. He did his grad work on LED's.

What the industry did is to have grad students cook up thousands of batches with different dopants and concentrations. They then measured the spectrum of the resulting LED's and stored the data in tables. Somewhere there must be a book filled with tables for LED colors.

Edit:

You can get close to the color you want by selecting a dopant which creates an ion center at a specific energy level but there is no formula for getting an exact color.

My information may be out of date though. I took solid state physics about 10 years ago.
 
Last edited:
  • #3
Hey, I found a nice pdf on LED's with some basic tables for LED colors. The color largely depends on the LED substrate material itself.

Check it out here
 
  • #4
@Okefenokee Great thank you, exactly what i was looking for
 
  • #5


Thank you for your question. The doping of a diode's pn junction is a crucial factor in determining its electromagnetic emission properties. To create a desired electromagnetic wavelength, we must first understand the relationship between the diode's doping concentration and its emission wavelength.

The emission wavelength of a diode is determined by the bandgap energy of the semiconductor material used in its construction. This bandgap energy is directly affected by the doping concentration of the pn junction. In general, a higher doping concentration results in a smaller bandgap energy and a shorter emission wavelength, while a lower doping concentration leads to a larger bandgap energy and a longer emission wavelength.

To determine the appropriate doping concentration for a desired emission wavelength, we can use the following steps:

1. Identify the desired emission wavelength: The first step is to determine the specific wavelength of electromagnetic radiation that we want the diode to emit.

2. Select the appropriate semiconductor material: Different semiconductor materials have different bandgap energies and therefore emit different wavelengths of light. Choose a material that has a bandgap energy that corresponds to the desired emission wavelength.

3. Calculate the required doping concentration: Using the bandgap energy and the desired emission wavelength, we can use the following formula to calculate the required doping concentration:

NA x ND = ni^2 x exp(-Eg/kT)

Where NA is the acceptor doping concentration, ND is the donor doping concentration, ni is the intrinsic carrier concentration, Eg is the bandgap energy, k is the Boltzmann constant, and T is the temperature.

4. Adjust the doping concentration: Once the required doping concentration is calculated, it can be adjusted by varying the amount of acceptor and donor impurities used during the diode fabrication process.

It is important to note that other factors such as temperature and material purity can also affect the emission wavelength of a diode. Therefore, it may be necessary to fine-tune the doping concentration through experimentation to achieve the desired result.

I hope this helps to answer your question. Please let me know if you have any further inquiries.
 

1. How do diodes work?

Diodes are electronic components that allow current to flow in only one direction. They consist of a semiconductor material, usually silicon, with a p-n junction. When a voltage is applied across the diode, it allows current to flow in the forward direction, but blocks it in the reverse direction.

2. What is the purpose of a diode in a circuit?

Diodes are used in circuits to control the direction of current flow, to convert AC to DC, and to regulate voltage levels. They are also used in signal processing and power supply circuits.

3. What is electromagnetic emission?

Electromagnetic emission refers to the energy that is radiated from an electronic device or circuit in the form of electromagnetic waves. This can include radio waves, microwaves, infrared radiation, and visible light.

4. How do diodes produce electromagnetic emission?

Diodes can produce electromagnetic emission when they are connected in a circuit and current is flowing through them. This emission is a result of the changing electric fields around the diode as the current flows through it.

5. Are there any safety concerns with electromagnetic emission from diodes?

In general, the electromagnetic emission from diodes is not harmful to humans. However, if a large number of diodes are emitting electromagnetic waves in close proximity, it can potentially interfere with other electronic devices and cause disruptions. It is important to follow proper safety protocols and regulations when using diodes in high-powered circuits.

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