By analyzing the difference between the actual P2N junction and the ideal model, the mathematical models of P2N junction diode and solar cell are established.
Model; Using the system simulation module library in Matlab, the simulation model is established, the parameters are set, the model equation is solved, and the 1 pair graph is drawn.
Under a certain illumination, the open-circuit voltage, short-circuit current and fill factor of solar cells are affected by different bypass resistances and series resistances.
And compared with the measured volt-ampere characteristics of silicon solar cells.
The results show that the equivalent bypass resistance and series resistance affect the open circuit voltage and short circuit current of the battery respectively. The simulation results and experimental measurements are 1.
The result is consistent 1.
P2N junction; Voltammetric characteristics; Equivalent circuit model; solar cell
China Library Classification. O475 document identification code a
Introduction to 0
P2N junction is the core of many microelectronic and optoelectronic devices.
The electrical and photoelectric characteristics of these semiconductor devices are made of P2N structure.
Through the analysis of these devices, the characteristics of P2N junction are determined.
The characteristic 1 semiconductor conduction is based on the drift of two carriers.
The realization of [1] 1 through movement, diffusion, generation and recombination is due to the non-P2N junction.
Linear characteristics, its current-voltage relationship can not be solved simply.
Analytical model determination 1. Although shockley's equation gives an ideal P2N.
The current-voltage relationship of the junction is very different from the actual device.
In practical devices, carriers are generated in the barrier region due to surface effect.
And its current-voltage characteristic only
Close to the ideal value 1 in a small range, when the DC voltage increases, I2V.
The curve changes from exponential relationship to linear relationship, and the reverse voltage increases at 1
It is also linear within a certain range, and the reverse voltage will be too large.
The breakdown of P2N junction occurs at 1.
This paper uses a simple circuit model to simulate the reality.
P2N junction, the influence of various practical parameters on the volt-ampere characteristics is discussed.
According to the actual parameters of solar cells under certain illumination
Resistance and series resistance affect its open circuit voltage, short circuit current and fill factor.
In order to analyze its volt-ampere characteristics, it is modeled by computer.
The 1 characteristic of the device is obtained, which is close to the actual device.
Voltammetric analysis and equivalent circuit of 1 P2N junction
The ideal P2N junction model meets the requirements of small implantation, abrupt depletion layer and glass.
Boltzmann boundary condition does not consider the generation of carriers in the depletion layer.
And the current-voltage relationship can be given by Shockley equation.
Get out, which means
J = J s exp
See ... (quodvide)
k T
- 1 ( 1)
Where v is the voltage at the P2N junction and j is the voltage at the P2N junction.
Current density, J s is the reverse saturation current 1 when the forward bias is large.
The exponential term in brackets is much larger than 1, so the second term can be omitted.
Slightly, the relationship between current density and voltage increases exponentially. When 1 is reverse biased,
When q| V | m k T, the exponential term tends to 0, and the current does not change with the voltage.
Change, tend to saturation value J s
1
The experimental measurement shows that the shockley equation is similar to the actual voltage of P2N junction.
The deviation of safety characteristics is large, mainly in two aspects: 1) DC voltage.
The theoretical value is smaller than the experimental value when it is small, and J2V when the DC voltage is large.
The relationship becomes linear; 2) when the bias voltage is reversed, the reverse current ratio theory
The value is much larger, the reverse current is not saturated, and it is slightly higher with the increase of reverse bias.
The increase of 1 shows that the ideal model cannot truly reflect the characteristics of the actual device.
Therefore, it is necessary to establish a more perfect P2N junction model [3] 1 in practical devices.
In devices, the generation, transmission and recombination of carriers will affect the P _ 2N junction.
The space charge field has an influence [4], which leads to the current and voltage of P2N junction.
The characteristic deviates from the ideal equation 1.
When forward biased, the carriers injected into the barrier region have a partial shape.
Composite current, the magnitude of which is directly proportional to the total electricity exp (qV/ 2 k T).
Current density is the sum of diffusion current density and composite current density 1
Silicon, under low forward bias, the composite current is dominant, so
The total current is greater than the current under ideal conditions, and the situation is complicated when the forward bias is high.
The combined current can be ignored.
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