Glossary

BRICK
A multicrystalline ingot is normally cut into 9, 16 or 25 equally sized bricks, from which the wafers will be cut. The footprint of the brick becomes the size of the wafer.

CRUCIBLEA quartz vessel used for melting and crystallization of polysilicon when producing multiand monocrystalline silicon ingots.

CRYSTAL Solid particle with a regular, periodic arrangement of atoms or molecules throughout the particle.

CRYSTALLIZATION The key process in the production of silicon ingots. For multicrystalline ingots the crystallization starts from the bottom of the crucible and proceeds towards the top as it is gradually cooled (directional solidification) under strict temperature and atmosphere control. In the production of monocrystalline ingots, a seed is lowered into the melt and subsequently pulled under strict control so as to form a growing monocrystal. dm2 Square decimeters, measurement typically used to quantify wafer production volumes.

ELECTRONIC GRADE SILICON (EG) Silicon with a purity of between 99.9999999 percent to 99.999999999 percent. (9N to 11N purity)

FEED-IN TARIFF Subsidy scheme where the owners of solar power systems receive a guaranteed, fixed price from the utilities for the electricity fed into the grid.

FLUIDISED BED REACTOR (FBR) TECHNOLOGY

A process for purification of silicon using a chemical reactor where solid particles (silicon) are suspended in an upward gas flow (typically silane or trichlorosilane) inside a tailor-made chamber.

GRID-CONNECTED SYSTEM Solar power system connected to the electric grid. Used in areas where other electricity systems are available.

IEA
International Energy Agency.

INGOT The silicon brick created when polysilicon is melted and crystallized in a furnace. Typical size for multicrystalline ingots are 680 x 680 mm with a weight of 250–300 kg. Monocrystalline ingots are cylindrical with typical diameters between 150 mm and 200 mm and a weight of 40–60 kg. kW Kilowatt, a unit of power (1 000 watts). kWh Kilowatt-hours. A unit of energy equal to that expended by one kilowatt in one hour.

MONOCRYSTALLINE SILICON Processed silicon where all the material consists of only one crystal.

MULTICRYSTALLINE SILICON
Processed silicon where the material consists of several small (typically 1–20 mm) crystal grains. MWp (106 WATTS peak). Unit of power. Used as output measure in the PV industry implying the potential peak effect produced by the produced solar cells.

OFF-GRID SYSTEM Solar power system not connected to the electric grid. Normally used in areas where grid-connected electricity is unavailable.

PHOTON INTERNATIONAL
International industry publication covering the PV industry.

PHOTOVOLTAIC (PV) EFFECT The generation of electricity when radiant energy, such as sunlight, falls on the boundary between two different substances (e.g. two different semiconductors).

POLYSILICON
Highly purified silicon used in the electronic and solar industry.


RENEWABLE ENERGY WORLD
International industry publication covering, among other industries, the global PV industry.

SIEMENS REACTOR Conventional reactor used for deposition of silane on long silicon rods. Used by most manufacturers of polysilicon.

SILANE
A compound gas consisting of hydrogen and silicon. An intermediate stage in the production of polysilicon.

SILICON The second most abundant element (after oxygen) in the earth’s crust. The raw material for solar grade silicon as well as electronic grade silicon.

SILICON WAFER
A thin slice of silicon used as the key component in a solar cell module.

SLURRY Cutting fluid used when sawing silicon bricks into wafers. Consists of silicon carbide and polyethylene glycol.

SOLARBUZZ
An international solar energy market research and consulting company.

SOLAR CELL Semiconductor device that creates electricity when exposed to sunlight. Normally made from silicon wafers.

SOLAR GRADE SILICON (SOG)
Silicon with 99.99999 percent to 99.999999 percent purity (7N to 8N purity).

SOLAR ENERGY Throughout this document the term solar energy refers to the generationu of electricity based on the photovoltaic effect. In other literature, solar energy may also include additional technologies for converting solar radiation into electricity or heat.

SOLAR MODULE
Interconnected solar cells encapsulated and protected in transparent materials that protect against humidity, air and mechanical damage. Normally, solar modules are made with a glass front and aluminum frame.

THIN-FILM Photovoltaic technology where the generation of solar energy takes place in a thin film of semiconductor material assembled in several layers. Conventional solar modules are made with wafers as the semiconductor material.

WIRE SAWING
The process where crystallized silicon bricks are cut into thin wafers using a saw with a web of thin metal wires. Wp (Watt peak) Power from solar cells is normally measured in watt when the solar cell is exposed to a standard sunlight irradiation (1000 W/sqm) typical for the peak time of a summer day. µm Micrometer (micron) 10–6 m. Measurement unit typically used when describing the thickness of wafers.