Solar cells are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current -- that is, electricity.
This electricity can then be used to power a load, such as a light or a tool. A number of solar cells electrically connected to each other and mounted in a support structure or frame is called a photovoltaic module. Modules are designed to supply electricity at a certain voltage, such as a common 12 volts system. The current produced is directly dependent on how much light strikes the module. Multiple modules can be wired together to form an array.
Additional energy provided will be converted into kinetic energy of the electron allowing it to move freely after being released. However, if only the energy equal to the work function is provided, the emitted electrons will remain on the surface of the metal, unable to move due to the lack of kinetic energy.
Furthermore, when the metal is fixed as a cathode in a vacuum tube with a receiving anode on the opposite side with an external circuit, the electrons that are ejected from the cathode will be attracted by the anode, which is maintained at a positive voltage and, therefore, a current is being transmitted within the vacuum, completing the circuit.
This phenomenon was first observed by French Physicist A. Becquerel in when he tried to produce a current between two plates of platinum and gold , immersed in a solution and that being exposed to light. He graduated from the University of California in with a degree in Computer Science. Follow him on Twitter HarlonMoss. Harlon Moss. Updated: March 7, Harlon Moss Harlon currently works as a quality moderator and content writer for Difference Wiki.
Previous Post. Next Post. A process in which interaction of light with a substance causes the emission of electrons from its surface is known as the photoelectric effect. A process in which interaction of light with two dissimilar objects causes the production of electrical voltage is called a photovoltaic effect. The idea of the photovoltaic effect was presented in by A. Becquerel, a French Physician. As a result of the incident light, the photovoltaic effect causes the movement of electrons in different materials.
It can observe in a cathode ray tube with the involvement of an anode and a cathode attached to an external circuit. This effect takes place between two different metals that combined with each other in a solution.
This effect takes place when the photons provide enough energy to cross the potential barrier of excitation. If an atom has many electrons, the outermost valence electrons are the only ones that undergo changes of state into different orbitals, since the inner electrons are "stuck" in between the nucleus and the valence electrons and hence have nowhere to go. The valence electrons cannot fill states that are already taken by the inner electrons, and so they can only take on higher states.
Electrons At the atomic level, electrons begin to act more like waves then particles.
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