Vitex Systems has announced a key breakthrough in protecting flexible copper indium gallium selenide (CIGS) solar cells against moisture and oxygen. The efficiency of flexible CIGS solar cells laminated with Vitex's Flexible Glass remained unchanged after being tested in extremely high temperatures and high humidity for over 1,100 hours.
With CIGS' potential for being produced using a low cost, roll-to-roll manufacturing process, it has quickly become one of the most promising thin-film photovoltaic technologies. However, similar to cadmium telluride (CdTe) cells, CIGS is also sensitive to moisture and oxygen. Commercially available flexible CIGS solar cells only have a guaranteed lifetime of two to three years because testing shows that their efficiencies degrade quickly in high-temperature and high-humidity environments. Some manufacturers have demonstrated that the use of rigid glass in the final modules extends product lifetime. However, there are added weight, costs (not only production, but also shipping and installation costs) and loss of flexibility when working with such rigid packaging.
The CIGS solar cells that achieved the lifetime record of over 1,100 hours were made on stainless-steel foil and laminated with Vitex's Flexible Glass 200 with a proprietary lamination process. With a total thickness of approximately 0.3 mm, the module was lightweight, flexible and unbreakable. According to the International Electrotechnical Commission (IEC) 61646 standard, the samples were subject to a damp heat test at 85 degrees Celsius (C) and a relative humidity (RH) of 85 percent for over 1,000 hours. After testing at Pacific Northwest National Laboratory (PNNL), the CIGS cells maintained more than 98 percent of their original efficiency after 1,100 hours -- exceeding the requirements of IEC's 61646 standard. The tests are continuing at PNNL to determine the ultimate lifetime of these devices.
Vitex Systems
