Theoretical study of volt ampere characteristic curves of photoelectric effect

Normal, either because the frequency response of the photocell is uneven, or because the second curve corresponds to a low transmission of the filter, or because the light source mercury lamp has a weak energy for this spectrum. Also, the accuracy of the measuring instrument can be a bit of a problem. Wait a minute.

The biggest possibility is that the gels have a low light transmission, followed by a little bit of a problem with the instrument. Then the photocell is not good.

photoelectric effectVoltammetry characteristic curveThe patterns shown are as follows:

Light shining on the photocathode of a photocell excites electrons of different energies. When the anode voltage is low, only the electrons with high energy can reach the anode, and when the anode voltage is raised, the electrons with low energy can also reach the anode.

Therefore, at the lower end of the curve, the higher the anode voltage, the greater the output current of the photocell.

According to Albert Einstein.

The optical quantum hypothesis states that the energy of a photon can only be transferred to one electron. When the light intensity.

At a certain time, the total number of photons is certain, and the total number of electrons that can be excited is certain;

After the anode voltage reaches a certain value, the current reaches saturation. In this case, the only way to increase the photocurrent is to increase the luminous flux.

A photocell is a photoelectric conversion device that can convert light energy into electrical energy. The volt-ampere characteristic curve of a photocell refers to the curve of the relationship between the current and voltage of the photocell, which is usually divided into the following segments:

1.Dark saturation zone: When the trapped cathode of the photocell is in a dark environment, that is, when there is no light irradiation, the electron saturation current of the photocell already exists, and at this time, the current of the photocell is basically unchanged and is in the dark saturation zone within a certain voltage range.

2.Linear region: When the light intensity gradually increases, the photocell is in the linear region, and its output current increases linearly with the increase of light intensity. In the sex zone, there is a sexual relationship between the photocell current and the light intensity.

3.Saturation zone: When the intensity of the absolute light of the jujube increases to a certain extent, the photocell enters the saturated zone, and the sensitivity of the photocell to light has been limited, even if the use of a higher intensity light source cannot further increase the output current of the photocell.

The reason for the formation of these regions is that the photoelectric effect is a quantum phenomenon, which is directly related to the energy, frequency and other factors of the photon, so under the change of light intensity, the photoelectrons on the surface of the cathode of the photocell will produce different electron release effects, resulting in the curve characteristics between current and voltage showing different characteristics.

Light shining on the BAI photocathode of the photocell can excite DU energy differently.

Zhi's electrons. When the anode voltage is low, only the electrons with high energy can reach the right anode, and the anode voltage is increased so that the low-energy electrons can also reach the anode. So at the lower end of the curve, the higher the anode voltage, the greater the output current of the photocell.

According to Einstein's quantum hypothesis of light, the energy of a photon can only be transferred to one electron. When the light intensity (luminous flux) is constant, the total number of photons is certain, and the total number of electrons that can be excited is certain, when the anode voltage rises to a certain value, all the excited electrons reach the anode, and then the anode voltage is increased, and no more photoelectrons will reach the anode. So when the anode voltage reaches a certain value, the current reaches saturation.

In this case, the only way to increase the photocurrent is to increase the luminous flux (increasing the number of photons).

At first, as the photocurrent increases, the voltage does not increase very much, but when it reaches a certain value (determined by the frequency of the light and the photocell component), it increases rapidly.