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 this technology one of the most promising for inexpensively generating electricity from sunshine. However, power conversion efficiencies remain at about 60% of what is thought to be required for commercially viability. Moreover, current devices incorporate both vacuum-deposited materials, which mitigate their supposed advantage of inexpensive production, and highly reactive materials, which lead to poor stability. This project will develop a new architecture for BHJ OPV, which will extend the range of operation further into the red (from ~620 nm to ~900 nm) 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 the need to use chemically unstable materials. True low-cost fabrication will be achieved by depositing transparent conducting oxides and metal back electrodes from nanoparticle solutions. The overall technical goal is to produce 1 cm2 inverted BHJ OPV devices via solvent deposition techniques with overall power conversion efficiency of 8 ¿ 10%, and with a drop in power output less than 20% over 1,000 hours of operation. Commercial Applications and other Benefits as described by the awardee: The new architecture should lead to increased efficiency and stability of BHJ OPV devices while minimizing materials and production costs, leading to devices that are less expensive than existing devices on a $/kW-h basis. Initial markets for BJ OPV are believed to lie in portable electronics and remote power generation, eventually trending towards on-site business and residential power generation.