Organic Photovoltaic (OPV) devices are a rapidly emerging PV technology due to their relatively low production costs and their ability to be processed by mature, high-throughput manufacturing techniques (i.e., roll-to-roll processing). OPV devices with a superstrate configuration, though, require costly screen printed silver or expensive evaporation of metal. Conversely, OPV devices with a substrate configuration utilize rough, inexpensive metal foils, making them a desirable alternative to superstrate configured OPV devices. However, the substrate configuration necessitates different interface layers between the rough, metal layer and the bulk heterojunction layer. For instance, a substrate OPV device with a ZnO interface layer, rough aluminum foils, and a PCBM:P3HT bulk heterojunction layer generates an open-circuit voltage (VOC) of less than 250 mV, compared to the full VOC of approximately 580 mV.
Thus, there is a need for an alternative interface layer to enhance the performance of substrate OPV devices on rough aluminum foils. NREL researchers have developed a novel alternative interface layer for substrate OPV devices on rough aluminum foils that is comprised of Ti/TiOx – ZnO. This novel interface layer is situated between a micron-rough Al foil layer and either a PCBM:P3HT or ICBA:P3HT bulk heterojunction absorber layer. With a PCBM:P3HT bulk heterojunction layer, a ZnO or Ti/TiOx interface layer generates nearly the full open circuit voltage of approximately 580 mV. Furthermore, when paired with a ICBA:P3HT bulk heterojunction layer, this novel Ti/TiOx – ZnO interface layer enables voltages of up to 780 mV.
For more information, contact Bill Hadley at Bill.Hadley@nrel.gov
Applications and Industries
- Organic PV
- Building-Integrated Photovoltaics
- Solar Cells
- Enables voltages up to 780 mV with ICBA:P3HT bulk heterojunction layers
- Enables full open circuit voltage of ~580 mV with PCBM:P3HT bulk heterojunction layers
- Can be processed with roll-to-roll manufacturing
- Low cost, eliminates the need for screen-printed silver