在NaYF4微晶中借助于Tm3+-Er3+耦合对间能量传递过程, 能够将一个高能291 nm紫外光光子剪裁成近红外796 nm和蓝色 476 nm两个光子。在291 nm (34 364 cm-1) 紫外光激发下, Tm3+的1I6能级首先被布居,再经过一个交叉弛豫过程使得Er3+的4I9/2和Tm3+的1G4能级同时被布居, 从而实现了Tm3+的1G4→3H6［476 nm (21 008 cm-1)］和Er3+的4I9/2→4I15/2［796 nm (12 563 cm-1)］辐射跃迁。估算了这种下转换过程的能量传递效率ηET和量子效率ηQE。通过这种量子剪裁可以解决光谱失配问题, 提高GaAs太阳能电池中的转换效率。

Energy up- and down-conversions are two efficient methods to resolve spectral mismatch. This paper reports down-conversions in solar cells based GaAs. The energy is transfered from Tm3+1I6→1G4 749 nm (13 356 cm-1) transition to Er3+4I9/2→4I15/2, 796 nm (12 563 cm-1) by the cross relaxations, under excitation of Tm3+3H6→1I6, 294 nm (34 364 cm-1), where the 1G4 level is used as an intermediate state. Then a high energy ultraviolet photon 294 nm can be cut into a near infrared 796nm photon and a blue 476 nm photon. Energy transfer efficiency and quantum cutting efficiency were estimated with experimental data. The spectral mismatch can be improved by the quantum cutting to enhance the conversion efficiency of solar cells.