Near‐Infrared Quantum Cutting via Downconversion Energy Transfers in Ho ³⁺ / Yb ³⁺ Codoped Tellurite Glass Ceramics

The different concentration of Ho 3+ / Yb 3+ codoped tellurite glasses were prepared by high‐temperature melting‐quenching method. On excitation of Ho 3+ ions with blue photon at 449 nm as well as ultraviolet ( UV ) photon at 360 nm, the near infrared emission at 977 nm from Yb 3+ and 981, 1020 nm from Ho 3+ , which could be absorbed by silicon and enhance the efficiency of the silicon‐based solar cell, were observed. The energy‐transfer process of Ho 3+ and Yb 3+ ions and involved mechanism have been investigated and discussed. The first‐order energy transfer ( ET ) through cross relaxation and a back ET from Yb 3+ to Ho 3+ occurred in the near‐infrared quantum cutting ( NIR QC ) system are proposed and verified. The NIR quantum efficiency achieved 166% when Yb 3+ doping concentration is 20 mol%.