The role of phosphor nanoparticles in high efficiency organic solar cells

• Phosphor nanoparticles doped in TiO2 film improve polymer solar cell performance.
• Short-circuit current and FF improved by phosphor nanoparticles dopant, giving 6.83% efficiency.
• Phosphor nanoparticles improve light harvesting and charge transport property.

Phosphor materials can be applied to enhance the energy conversion efficiency of a solar cell. Such materials convert low-energy transmitted photons to higher-energy photons that can be absorbed by the cell, substantially decreasing the spectral mismatch between the cell and the solar spectrum. In this paper, the efficiency of organic solar cells (OSCs) was improved by incorporating phosphor nanoparticles as dual functionality into TiO2 cathode buffer layer. The dependence of devices performance on doping concentration of NaYF4:Yb3+,Er3+ nanoparticles was investigated. A high power conversion efficiency of 6.83% was achieved, which mainly attributes to the increase of short-circuit density. The absorption spectrum indicates that light-harvesting of doped films is higher than undoped film, which originates from scattering effect and NIR spectrum sensitization of phosphor nanoparticles. The measurement of electron-only devices shows that electron transport property of doped devices was apparently improved. Impedance spectroscopy reveals that the diffusion coefficient and carrier mobility were greatly enhanced. This study demonstrates that phosphor nanoparticles doping is useful for fabricating high performance OSCs.

The light-harvesting and electron carrier transport property are greatly improve by introduction of phosphor nanoparticles.Figure optionsDownload as PowerPoint slide