Solar cells are devices that use the photoelectric effect of semiconductor materials to convert solar energy into electrical energy.
The basic process of photovoltaic effect: assuming that light shines on the solar cell and the light is admitted at the interface layer, the photons with a Sufficient energy can remove electrons in P-type silicon and N-type silicon excited by covalent bonds, resulting in the generation of electron-hole pairs.
The electrons and holes adjacent to the interface layer will be separated from each other by the action of the electric field of the space charge before recombination. The electrons move towards the positively charged N region and the holes move towards the negatively charged P region. The separation of charges across the interface layer will form an outward testable voltage between theP region and the N region. At this point, electrodes can be added to both sides of the silicon wafer and connected to a voltmeter.
For crystalline silicon solar cells, the typical value of open circuit voltage is 0.5 to 0.6 V. The more electron-hole pairs generated by the light illuminating the interface layer, the higher the current. The more light energy the interface layer receives, the larger the surface area of the interface layer, i.e. the cell, and the greater the current formed in the solar cell.