Upconversion Luminescence from Ln3+(Ho3+,Pr3+) Ion-Doped BaCl2 Particles via NIR Light of Sun Excitation

Generation of visible photons by upconverting materials under excitation by the near-infrared part of sunlight is very attractive for complete utilization of solar energy. Visible upconversion luminescence is efficiently generated in BaCl2:Ln3+ (Ho3+ or Pr3+) particles via excitation with broad band near-infrared part of sunlight. We observed greatly enhanced photocurrent response from the thin-film hydrogenated amorphous silicon solar cell covered with the upconversion layer of BaCl2:Ho3+ phosphor, which demonstrates a prospective application for near-infrared photoresponse devices.