Here is a probable means to boost the efficiency of photovoltaics by nearly 80 percent. Investigators from the Oak Ridge National Laboratory have now crafted a 3-D nanocone-based solar cell platform to improve the light-to-power conversion efficiency of photovoltaics. This technology can supposedly overcome the problem of poor transport of charges generated by solar photons.
The negative electrons and positive holes apparently become trapped by defects in bulk materials and their interfaces which in turn degrade performance. In order to solve the entrapment problems that reduce solar cell efficiency, investigators developed a nanocone-based solar cell. They also invented methods to synthesize these cells and demonstrated better charge collection efficiency. The new solar structure probably contains n-type nanocones that are surrounded by a p-type semiconductor.
These n-type nanoncones are allegedly made from zinc oxide and serve as the junction framework as well as the electron conductor. The p-type matrix, on the other hand, fabricated with the help of polycrystalline cadmium telluride, may serve as the primary photon absorber medium and hole conductor. Jun Xu, a member of ORNL’s Chemical Sciences Division and colleagues claim to have achieved a light-to-power conversion efficiency of 3.2 percent as compared to 1.8 percent efficiency of conventional planar structure of the same materials.
The three-dimensional structure supposedly offers an intrinsic electric field distribution that promotes efficient charge transport and high efficiency in converting energy from sunlight into electricity. The key features of the solar material presumably encompass its unique electric field distribution that achieves efficient charge transport, the synthesis of nanocones using inexpensive proprietary methods and the minimization of defects along with voids in semiconductors.
The latter reportedly provides improved electric and optical properties for conversion of solar photons to electricity. Thanks to efficient charge transport, the new solar cell can seemingly withstand defective materials and simultaneously decrease cost of manufacturing next-generation solar cells. The important concept behind this invention appears its nanocone shape that can produce a high electric field in the vicinity of the tip junction.
The research was supported by the Laboratory Directed Research and Development program and the Department of Energy’s Office of Nonproliferation Research and Engineering.