Why Organic Thin-Film Solar Cells?
Research scientists at the Stanford Photonics Research Center are pursuing aggressive research and development activities focused on the development of advanced, light-weight, flexible, organic thin-film (OTF) solar cells. These scientists believe  that minimum material cost and easy-to-process organic materials are the principal reasons for the development and manufacturing of these solar cells to meet electrical energy requirements at reasonable costs. The low-cost organic material is readily available in sufficient abundance, even to cover very large areas for solar panel installation. The OTF solar cells can be fabricated on light-weight flexible substrates in large areas with low-cost manufacturing techniques, such as roll-to-roll coating, with zero material waste. Currently, the material scientists anticipate no serious reliability and lifetime problems for these devices. If these organic materials can demonstrate lifetimes better than 20 years that is enjoyed by silicon-based solar cells, then one must proceed with the design, development, test, and evaluation of organic thin-film solar cells. Power conversion efficiency of thin-film organic solar cells is not very impressive compared to amorphous silicon devices even after the research and development activities over the last 15 years, according to information published in Photonics Spectra (December 2007). Progress on power conversion efficiencies for thin-film organic solar cells is quite evident from the data shown in Table 5.7.
The efficiency data is at AM1.5 sunlight conditions and under solar radiation intensity of 100 mW/cm2. Note conversion efficiencies will be much higher under higher radiation intensities or at higher sunlight concentration factors.