Manufacturing

The performance of a solar module depends on its efficiency of converting sunlight into electricity. The latest technology is paving way to improve the efficiency and targeting to hold down the production cost of the module.

Solar Technologies FZE intends to be the largest manufacturer of large size, highly efficient and reliable thin-film solar panels in all of West Asia. The first plant with a capacity of 130 MW per year is being set up in Dubai, UAE for the production of Thin film BIPV modules, with due consideration for further expansion. The technology is provided by Applied Materials, the global leader in thin-film and semiconductor industry. Each module shall have a size of 5.7 square meter at 8.5% stable efficiency which is the largest size substrate ever.

Tandem Junction Thin-film Solar Module Production Line




TECHNOLOGY

Photovoltaic technology, the scientific term used to describe solar energy, involves the generation of electricity from light. The solar industry is based on photovoltaic (PV) solar modules that convert sunlight directly into electricity using semiconductor technologies related to those at the heart of integrated circuits, flat panel televisions and other industrial products. The most common semi-conductor material used in photovoltaic modules is silicon, an element most commonly found in sand. When light shines on the semi conductor, the electric field across the junction between the layers causes electricity to flow, generating DC current. The greater the intensity of the light, the greater is the flow of electricity. A photovoltaic system does not therefore need bright sunlight in order to operate. The process of converting light (photons) to electricity (voltage) is called the photovoltaic (PV) effect.

Thin film modules are constructed by depositing extremely thin layers of photosensitive materials on a low cost backing such as glass. Microcrystalline technology, in particular the combination of amorphous silicon and microcrystalline silicon (a-Si/μ-Si) is the latest approach with encouraging results. Solar Technologies is adapting this technology. a-Si/μ-Si modules are built by depositing a thin layer of silicon on top of the substrate, like glass. Chemical vapor deposition (CVD) is the process that deposits solid thin films on substrates by reaction of vapor phase chemicals (reactants). Plasma enhanced chemical vapor deposition (PECVD) tool deposits a thin film on glass substrates. Radio frequency (RF) power is introduced to ionize the process gases and to promote the formation of a thin film silicon layer composed of a p layer, an i layer, and a n layer on the glass substrate. Further a back contact is formed by depositing zinc oxide, zinc, aluminum, silver, or nickel vanadium. The Ag deposition promotes conductivity and light reflection. The NiV deposition layer is to provide a surface for solder. Metal interconnects are used to bring the generated electric current out of the modules. After metallization, photovoltaic modules are laminated to the back glass with an adhesive polymer layer (Polyvinyl Butyral) for mechanical and environmental protection The J-Box assemblies are aligned and attaches to the back surface of module, where connection tabs are soldered to the module cross bus.