New Dopants for Iron (II) Oxide-Based Solar Energy Conversion Devices: Enhanced Conductivity

Web Published:

Princeton Docket # 12-2774


Solar energy conversion devices include photovoltaics, photoelectrochemical cells and photocatalysts, which convert the energy of sunlight into electricity and produce fuels from carbon dioxide and water.  Different materials for making the solar energy conversion devices exhibit different energy conversion efficiencies and entail different costs.  Currently, the most prevalent semiconductor material used in the solar industry is (poly)crystalline silicon for photovoltaics, which requires an expensive purification process to obtain pure and defect-free materials.  First row transition metal oxides are much more affordable, because of their reasonable abundance, non-toxicity, ease of synthesis, and low cost for scaled-up manufacturing. However, a major setback of many transition metal oxides, which limits conversion efficiency, is low conductivity. 


Wüstite [i.e., iron (II) oxide] is of particular interest, as it is inexpensive and non-toxic, and has a band gap in the optimal range for absorbing solar energy.  However, wüstite suffers from thermodynamic instability in the bulk phase, but this disadvantage can be overcome by alloying with other stable oxides and potentially by nanostructuring. 


Using first-principles quantum mechanics calculations, researchers at Princeton University have discovered that adding small concentrations of inexpensive additives (dopants) to Fe(II) metal oxide alloys can increase the number of charge carriers without adding charge trapping sites, and therefore can strongly enhance conductivity.  Thus, the new doped materials should improve the photon-to-current/fuel conversion efficiency of solar energy conversion devices.



·         Low cost

·         Enhanced Conductivity

·         Improved efficiency



·         Semiconductors in photovoltaic cells

·         Electrodes in photoelectrochemical cells

·         Photocatalysts for fuel production


Intellectual Property Status

Patent protection is pending.


Princeton is seeking to identify appropriate partners for the further development and commercialization of this technology.




Michael Tyerech

Princeton University Office of Technology Licensing



Laurie Bagley

Princeton University Office of Technology Licensing





Patent Information:
For Information, Contact:
Chris Wright
Licensing Associate
Princeton University
Emily Carter
Maytal Toroker