A New Three-Part Architecture for Efficient and Stable Bulk Heterojunction OPV Devices

Rapid and encouraging progress in bulk heterojunction organic photovoltaics (BHJ OPV) has made them one of the most promising new technologies for inexpensively generating electricity from sunshine. However, power conversion efficiencies remain about ~60% of what is thought to be required in order for them to be commercially viable. Moreover, the champion devices incorporate both vacuum-deposited materials, which mitigate their advantage of inexpensive production, and highly reactive materials, which lead to poor stability. Our approach is a new architecture for BHJ OPV, which simultaneously extends the range of operation further into the red (from ~630 nm to ~850 nm and beyond) while retaining the excellent properties of the poly(3-hexyl)thiophene:fullerene blend for energy conversion at lower wavelengths. Issues related to device stability will be addressed by eliminating chemically unstable materials, which will prove to be unnecessary in the new architecture. True low-cost fabrication will also be achieved by limiting the cost of the organic materials and depositing both transparent conducting oxides and metal back electrodes from nanoparticle solutions. Commercial Applications and Other Benefits: The new architecture proposed will lead to increased efficiency and stability while minimizing materials and production costs. That combination will lead to BHJ OPV devices that are less expensive than existing devices on a $/kW*h basis, enabling commercial utilization of BHJ OPV for electrical power production. Initial markets for BJ OPV are believed to lie in flexible and portable electronics for remote power generation, trending towards on-site business and residential power generation as manufacturing techniques are up-scaled and refined.