Solution Processed Bulk Heterojunction Organic Solar Cells Based on Near-IR Absorbing Soluble Phthalocyanines

Invention: This invention demonstrates excellent near-IR photoactivity for solution-processed Bulk Heterojunction (BHJ) OPV device. For the optimized BHJ devices the VOC is (a) higher than the corresponding solution processed Planar heterojunction (PHJ) device fabricated from octahexylthio-substituted C6-TiOPc and (b) comparable to the vacuum-deposited PHJ fabricated from Phase-I of the unmodified TiOPc. Background: The solar cells in the current invention convert sunlight in the near-IR region of the solar spectrum to electricity and they are constructed from a soluble small molecule rather than polymer donor materials. An Organic Photovoltaic (OPV) device efficiency can be significantly improved if the optical absorption of the active-layer is extended to the near-IR region of the solar spectrum where most solar photons are incident without sacrificing the VOC. Applications: 1) They can be deposited in thin-films over large areas using techniques such as reel-to-reel wet coating ink-jet printing and spin-coating 2) Can facilitate the formation of large area light-weight low-cost and potentially flexible devices.