The demands of the solar energy market require the development of advanced photovoltaic technologies. The DOE is seeking to develop organic PV technologies that are more efficient, long lasting and cost competitive to traditional ones. Organic PV (OPVs) have become well recognizedas an important candidate for future solar power products, although their efficiency is not exceeding 6-7%. The overall objective of this Phase II STTR project is the development and fabrication of tandem and multijunction OPVs with efficiency increased to the level of > 10-15 % which will open new markets for OPV, such as OPV power for portable devices: notebook PC, cell phones, outdoor solar lighting. A critical part of the proposed tandem OPV device operation is the transparent interconnecting layer, which allows the connection of sub-cell OPVs in a new parallel architecture. Carbon nanotube sheets of present program have been proven as interconnecting layers (called as
