Upconverting BiYO3 nanophosphors in DSSCs applications

BiYO3: Er3+/Yb3+ nanophosphors synthesized by so-gel technique have been characterized by using XRD, reflectance, FTIR and FESEM analysis. Upon excitation at 980 nm with a CW diode laser radiation the BiYO3: Er3+/Yb3+ nanophosphors exhibit UC emission bands corresponding to the H-2(11/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2) transitions. Effect of incorporation of UC nanophosphors in DSSCs containing TiO2 nanoparticles on light to electric energy conversion efficiency and charge transfer dynamics has been discussed. In DSSCs containing UC nanophosphors, the improvement in the power conversion efficiency has been explained due to enhancement in the light harvesting property followed by the NIR to visible frequency upconversion process. BiYO3: Er3+/Yb3+ UC nanophosphors for security ink and an anti-counterfeiting application has been also demonstrated.