DescriptionThe majority of lab-scale organic and polymer solar cells (OPV) are very small with <<0.5 cm2 using ITO glass, spin coating, evaporation, inert atmosphere, and optimum conditions. Obviously, the cells can lead to record efficiencies - but they are far beyond real world applications due to miniscule power output. Transfer to large-scale devices with an appropriate power output is hardly possible.
Here, we present the route from roll and roll-to-roll processed test devices to multi square meter large polymer solar cell modules with hundreds of Watts output - fully roll-to-roll (R2R) produced under vacuum-free and ambient conditions without using indium tin oxide (ITO) as transparent conductive electrode. ITO has the highest impact on the embodied energy in OPV devices and is replaced by an all additive printed and coated electrode based on flexo printed silver grid, rotary screen printed PEDOT:PSS, and slot-die coated zinc oxide (Flextrode). The production speed for each layer is beyond 10 m/min independently of the individual layout for different devices.
Model cells with at least 1 cm2 are fabricated on a rollcoater, which allows easy transfer to the R2R line for larger test modules with e.g. 8 serially connected cells and the size of a postcard (freeOPV, active area >50 cm2). Both routes allow the testing of new polymers, functional inks, and device structures such as tandem stacks with minimum amount of material input but large number of devices for statistical analyses.
Finally, OPV modules with high power output for real-world applications and grid-connection can be easily produced based on the Infinity concept developed in our group. Virtually infinite large solar cell modules are based on thousands of serially connected cells entirely fabricated using very fast R2R printing and coating processes. No manual labour or proprietary processes are required for bussing and interconnection of submodules. The serial connection is completed throughout the print run due to an optimized pattern layout. The advantage of the Infinity concept is the fabrication of high-voltage OPV modules with active areas beyond several square meters (21000 cells = 14.7 m2, 100 m long) and stabilized power outputs of >220 W using the standard active layer material P3HT:PCBM. The module has only two terminal connectors for minimized wiring during the setup of module arrays. The installation of a 100 m long module takes less than one minute. A parallel-connected array with outputs >1.3 kW and rather low efficient material (<2%) was built. An entire solarpark based on such OPV modules has a low energy payback time of just 0.5 years.
|Period||3 Dec 2014|
|Event title||2014 MRS Fall Meeting & Exhibit|
|Location||Boston, United States|