title: Broadband down-conversion for silicon solar cell by ZnSe/phosphor heterostructure.
abstract: Down-conversion is a feasible way to improve conversion efficiency of silicon solar cell. However, the width of excitation band for down-converter based on trivalent lanthanide ions is still not satisfying. Here, we designed and fabricated a heterostructural down-converter composed of Y₂O₃: [(Tb³⁺-Yb³⁺), Li⁺] quantum cutting phosphor and ZnSe. The ZnSe phase was used to absorb the incident light with energy larger than its bandgap, and transfer the energy to Tb³⁺-Yb³⁺ quantum cutting couple. Short-wavelength incident light was finally converted into a strong Yb³⁺ emission at about 1000 nm, locating at the maximal spectral response of silicon solar cell. The excitation band of the down-conversion covers a wide region of 250-550 nm. Benefiting from the energy match between ZnSe bandgap and ⁷F₆→⁵D₄ absorption of Tb³⁺ ions, the bandwidth of down-conversion is almost maximized.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Wu
authors.forename: Fanzhi
authors.initials: F
authors.lastname: Meng
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yingning
authors.initials: Y
authors.lastname: Yu
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Meng