Novel Solar Cell with Dramatically Increased Efficiency

Generates Electricity by Harvesting Energy from Entire Spectrum of Light

This revolutionary solar cell efficiently generates electricity by harvesting energy from the entire spectrum of light. Electricity production is the number one use of renewable energy in the United States, with 17.1% percent of all renewable energy being used by this sector in 2017, according to the Energy Information Administration (EIA). According to their recent energy review, approximately 24 billion killowatthours (kWh) of electricity were generated from solar photovoltaic cells in 2017. Although the efficiency of organic solar cells has been improving steadily since their initial creation, the available forms of solar cell energy still offer an extremely low rate energy production. Available solar cells can only generate electricity within a small range of wavelengths of light, contributing to unreliable efficiencies. For instance, inorganic or hybrid solar cells use inorganic nanocrystals, which provide power conversion efficiencies in the range of two to three percent. These efficiencies are significantly lower than other forms of energy sources, making solar cells unreliable in commercial settings.

Researchers at the University of Florida have developed an efficient solar cell architecture that harvests energy from the full spectrum of light. Using such architecture, large scale solar photovoltaic systems may provide a sustainable alternative to fossil fuels.

Applications

Highly efficient solar cell that harvests energy from the entire light spectrum to generate electricity

Advantages

• Affords manufacturers the opportunity to construct solar cells from low-cost materials, providing a marketable advantage in the rapidly growing field of alternative energy
• Functions using alloyed semiconductor nanocrystals, yielding maximum efficiency in electricity production
• Utilizes two independent variables to tune its band gap and electron affinity, making it possible to simultaneously achieve the optimized band gap and electron affinity for maximum efficiency

Technology

These solar cells independently optimize the band gap—the energy difference between the conduction and valence bands—and the electron affinity—the energy difference between the vacuum level and the conduction band. Within the device are alloyed semiconductor nanocrystals instead of conventional binary semiconductors, enhancing the efficiency of the device. For nanocrystals based on ternary semiconductor alloys, this solar cell has two independent variables to tune its band gap and electron affinity, making it possible to simultaneously achieve the optimized band gap and electron affinity. For nanocrystals based on quaternary semiconductor alloys, the additional composition variable will provide even more freedom to optimize the two important material properties.