1. Solar Cell Structure and Working Principle

Solar cell is referred to as electric eye or photovoltaic cell. It is a semiconductor device which transforms light into electricity. The principle is based upon photovoltaic effect of P-N junction. When the cell surface receives light, photoelectron-hole couples are generated in the cell and diffuse to P-N junction. Due to junction field, these couples are seperated with electrons moving toward N-zone and holes toward P-zone, which produces photovoltage between P-zone and N-zone and thus current when an external load(such as a light bulb) is connected.

2. Solar Energy System Working

PV modules generate electricity when receiving sunlight. After reverse converting and controling, it is partly saved in the storage cell, partly connected to the load directly or transported to the public grid.