Toshiba has developed a new coating method for the perovskite layer that boosts power conversion efficiency (PCE) to 15.1% for Toshiba’s 703cm2 module, the highest for any large, polymer film-based perovskite photovoltaic module. The innovative coating method for perovskite layer also greatly reduces production time and costs, contributing to a lower cost for solar power generation. Today’s most widely used photovoltaic modules are made with crystalline silicon and are heavy, and this, plus their rigidity, limits where they can be installed. The polymer film-based perovskite photovoltaic module is an attractive next-generation alternative, as it is thin, light and flexible, and can be installed in locations where it is difficult to use silicon photovoltaic modules, such as low load-bearing roofs and office windows.
Toshiba’s latest breakthrough is the development of a new perovskite layer coating method. This multi-step approach had a low coating rate and often left unreacted sections in the perovskite layer. Toshiba has developed a one-step meniscus coating method that uses improved ink, film drying processes and production equipment to form a uniform perovskite layer over an area as large as 703cm2.
These innovations halve the steps for deposition of the perovskite layer, and raise the coating speed to 6 meters per minute on a 5×5 cm module, a rate that meets requirements for mass production. Toshiba estimates that the new perovskite photovoltaic modules would generate power equivalent to two-thirds of the annual power consumption by homes in Tokyo if installed on a roof area of 164.9km, roughly equal to the roof surface area of all buildings in Tokyo. Toshiba will continue research on perovskite photovoltaic modules, aiming to increase PCE to 20% or more, and to enlarge the active area to 900cm, the size required for practical application.
