What are the main sources of resistance when solar cell devices are operating?

Sunlight.

The operating principle of solar cells is based on the photovoltaic effect of the PN junction of the semiconductor. The so-called photovoltaic effect is an effect in which when an object is exposed to light, the state of charge distribution in the object changes to generate an electromotive force and a current. When sunlight or other light irradiates the PN junction of a semiconductor, a voltage appears on both sides of the PN junction, called photovoltage.

The photogenerated voltage from the battery is consumed by the series resistance, causing a drop in the output voltage. The parallel resistance mainly comes from the leakage of the battery PN junction, including the drain electrode inside the PN junction (crystal defects and external doped deposits) and the leakage current at the edge of the junction .

The electromotive force of each solar cell is 0.50 V and the short circuit current is 0.04 A. What is the internal resistance of the battery? Nowadays, several such solar cells are connected in series (

This can be solved using Ohm's law of the whole circuit. When several solar cells are connected in series, the output voltage is theoretically equal to the voltage supplied by each cell multiplied by the cell number is similar to series connection of batteries, but the actual output voltage will be lower than this value, because each battery piece itself has also a resistance In the series circuit, the total resistance of these battery pieces will also "consume" or "distribute" some of it, so the output voltage will be reduced, which will also affect the power.

If these battery slices are connected in parallel, the total output voltage will be slightly lower.ure to the voltage supplied by each battery slice, also because of the battery slice. The circuit itself also has resistance after connecting in parallel.

However, whatever the situation, when the external resistance (resistance of the electrical device) is equal to the resistance of the power supply itself composed of battery cells, the circuit will have a power maximum output

The internal resistance of the battery r=.

Rated electrical current "2.0 V, 0.04 W" I1=

Suppose that a total of n batteries of this type are needed

Then nE=I1?nr+U,

Put in the solution Get n=8

Answer: It takes 8 of. these solar cells for the device to work properly