Efficient zinc sulfide cathode layers for organic photovoltaic applications via ntype doping

Organic photovoltaics (OPVs) have the potential to enable low-cost conversion of sunlight into usable energy. Bulk and interface properties are equally important in optimizing performance in these devices. A critical component in OPVs is the cathode-side window layer, composed of a wide band gap n-type semiconductor that acts to (1) block excitons from quenching at the cathode, (2) protect the active layers from damage during the cathode deposition, (3) reduce Schottky barriers for improved charge collection, and (4) extend the lifetime of the device. The cathode-side window layer must also be optically transparent to limit parasitic absorption at shorter wavelengths. Bathocuproine (BCP) is commonly used as the cathode-side buffer layer in OPVs due to its wide energy gap that effectively blocks excitons. However, BCP's low glass transition temperature and molecular weight limit its use in long-lifetime applications due to poor thermal stability that leads to catastrophic crystallization and can result in reduced conductivity and poor device lifetime. While cadmium-based window layers such as cadmium sulfide (CdS) (2.4 eV band gap) offer a potential alternative and have the best electrical performance over nearly all other known window layers in analogous thin-film inorganic photovoltaics, device fabrication presents healthy hazards due to the high toxicity of cadmium and the small band gap limit blue/UV photoresponse. Because the catalog of high-performance window layers in inorganic thin film photovoltaics is largely limited to cadmium-based compounds, it is advantageous to find a greater range of alternatives that can also provide variability in energy level matching and improved transmission characteristics. If you are looking for high quality, high purity, and cost-effective zinc sulfide, or if you require the latest price of zinc sulfide, please feel free to email contact mis-asia.