What is amorphous silicon?

amorphous silicon is a form of silicon, the second most occurring natural element on the ground. However, it differs from silicon in that it is non -crystallized and disturbed in the same way as the common glass, which means that some atoms in its chemical structure resist binding. These so -called "hanging" bonds affect the own properties of the material, namely it give it a higher density of defects, which concerns a number of naturally occurring imperfections. This substance, often shortened to a -i , still offers several advantages over crystalline silicon, which is more convenient for use in the production of thin films for the coating of various electronic components, especially photovoltaic (PV) systems. For example, it can be applied to large areas in a more homogeneous way than silicon and at very low temperatures, allowing it to grip glass, plastic and metals.

before amorphic silicon can be applied as a thin film to certain materials such as solar cells must go through hydrogenTerial greater stability and durability. This means that the hanging links must undergo "passive", a process in which disordered bonds in each layer of silicon cells are saturated with atomic hydrogen, while under pressure between the layers of transparent conductor and metal pad, usually tinide and aluminum. This modification allows greater flexibility in terms of how the material can be stored, and also offers greater control over its voltage properties. As a result, amorphous silicon can be used in thin films used to produce various low -voltage devices such as pocket and watch calculators.

Another advantage of using amorphous silicon thin film above crystalline silicon is that the former absorbs up to 40 times more sunlight. In this case, only a very thin film coating is necessary to absorb 90 percent or more direct sunlight. In fact, the coating must only be 0.000 039 37 inches or one micrometer in thickness. To give it toPerspectives have one strand of human hair thickness 100 times larger. This attribute increases the cost efficiency of the use of amorphous silicon in thin films technologies.

The only disadvantage of using amorphous silicon in solar cell applications is something known as the Staeber-Wonski effect. For reasons that are not fully understood, cells in the material tend to reduce voltage output by up to 20 percent after initial exposure to natural sunlight. However, the material reaches the stability of electrical output after one to two months.