An Oak Ridge National Laboratory team led by Jun Xu has enhanced the light-to-energy conversion efficiency of PV by almost 80% with a three-dimensional nanocone-based solar cell system.
The technology helps enhance transport of charges produced by solar photons. The negative electrons and positive holes are constrained by flaws in volume materials and their interfaces, disrupting performance.
Xu, a member of the Chemical Sciences Division at the lab,says that the trapping lowers efficiency of the solar cells. It was to address this problem that the team designed a nanocone-based solar cell and techniques to synthesize these cells for enhanced charge collection.
The design comprises n-type nanocones enclosed by a p-type semiconductor. The zinc oxide nanoncones act as the interface and electron conductor. The p-type polycrystalline cadmium telluride matrix acts as a photon absorber and also as a hole conductor. The team derived a light-to-energy conversion efficiency in laboratory trials of 3.2%. The three dimensional design delivers an electric field that enables charge transport and conversion of sunlight into energy. The material helps reduce flaws and gaps in semiconductors that enhance electric and optical traits of solar photons. Due to the proficient charge transport, the new solar cell can endure faulty materials and lessen cost in manufacturing advanced solar cells.
The research project was funded by the Laboratory Directed Research and Development program and the Department of Energy's Office of Nonproliferation Research and Engineering.
Source: http://ornl.gov