Max Photo Current Calculation Using Platinum's Work Function

In summary, the work function of platinum is 6.35 eV and the irradiation power is 1.27 W. To find the maximal photo current, you can use the equation P=VI, but the voltage part is unclear. The current will depend on how many electrons can be freed in one second, with each one needing the energy wo. The given power indicates the amount of energy available per second.
  • #1
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1. Platinum has a very high work function of wo = 6.35 eV.What is the maximal photo current Io that can be achieved with an irradiation power of
P = 1.27 W ?




Homework Equations


hf = wo


The Attempt at a Solution


Well, Since the only information they give here is the work function, then i assume that it is related to the voltage. I'm trying to use P=VI to find I but it's the voltage part that's confusing me.
 
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  • #2
The current is charge per unit time so it will depend on how many electrons can you break free in one second.
For each one you need the energy wo.
The given power tells you how much energy is available per second...
 
  • #3
For the voltage, I'm thinking of using V = hf/q. So I'm thinking of using the given work function as the energy and then solving for V, but I'm not sure if that's the right approach. Any suggestions?I would approach this problem by first understanding the relationship between the work function and the maximum photo current. The work function represents the minimum energy required for an electron to escape from the surface of a material. In other words, it is the energy needed to overcome the attractive forces of the material and become a free electron.

In the context of this problem, the work function of platinum tells us that it requires 6.35 eV of energy for an electron to escape from its surface. This energy can come from an external source, such as light. When light with a frequency (f) corresponding to 6.35 eV is incident on the platinum surface, it can provide the necessary energy to release electrons from the metal and create a current.

Now, to find the maximum photo current (Io) that can be achieved with an irradiation power of P = 1.27 W, we can use the formula Io = P/hf, where h is Planck's constant. This formula tells us that the maximum photo current is directly proportional to the irradiation power and inversely proportional to the frequency of the incident light.

Substituting the given values, we get Io = (1.27 W)/(6.63 x 10^-34 J s x 6.35 eV) = 3.29 x 10^19 electrons per second.

In conclusion, the maximal photo current that can be achieved with an irradiation power of P = 1.27 W is 3.29 x 10^19 electrons per second. This value can be increased by increasing the irradiation power or using light with a higher frequency.
 

FAQ: Max Photo Current Calculation Using Platinum's Work Function

1. What is the purpose of calculating the max photo current using platinum's work function?

The purpose of calculating the max photo current using platinum's work function is to determine the maximum amount of current that can be generated by a photoelectric material when exposed to light. This calculation is important in understanding the efficiency and performance of a photoelectric device.

2. How is platinum's work function related to the max photo current?

Platinum's work function, also known as its electron affinity, is the amount of energy required to remove an electron from the surface of the material. This work function is directly related to the maximum amount of current that can be generated by the material, as a lower work function means it is easier for electrons to be released and contribute to the current.

3. What factors affect the max photo current calculation using platinum's work function?

The main factors that affect the max photo current calculation using platinum's work function are the intensity and wavelength of the incident light, the surface area of the material, and the properties of the material itself such as its band gap and electron mobility.

4. How is the max photo current calculated using platinum's work function?

The max photo current can be calculated using the following equation: I = Φ × A × (1 - R) × η, where I is the photo current, Φ is the work function of platinum, A is the surface area of the material, R is the reflectance of the material, and η is the quantum efficiency of the material. This equation takes into account the factors that affect the max photo current and provides a more accurate calculation.

5. Why is platinum commonly used in max photo current calculations?

Platinum is commonly used in max photo current calculations because it has a relatively low work function compared to other materials, making it efficient in generating current from light. Additionally, platinum is a stable and durable material, making it suitable for use in various photoelectric devices.

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