23 September 2016 Broadband-sensitive upconverters co-doped with Er3+ and Ni2+ for crystalline silicon solar cells
Author Affiliations +
We have demonstrated broadband sensitization of Er3+-doped upconverters coupled with crystalline silicon (c-Si) solar cells by introducing Ni2+ co-dopants into ABO3-type perovskite host materials such as La(Ga,Sc,In)O3 and CaZrO3. The Ni2+ sensitizers absorb 1.1−1.45 μm photons, which are not absorbed by either c-Si or Er3+, and transfer the energies to the Er3+ emitters. Thus, 1.1−1.45 μm photons are also upconverted to 0.98 μm photons, in addition to 1.45−1.6 μm photons that are directly absorbed by the Er3+. To compensate the charge imbalance caused by introducing divalent Ni2+ ions into the trivalent (Ga3+, Sc3+, and In3+) and tetravalent (Zr4+) sites, Nb5+ co-dopants were incorporated. Similarly, codoping with monovalent ions (Li+, Na+, K+) notably enhanced the upconversion emission when the Ca2+ sites were substituted with the Er3+ ions. These broadband-sensitive upconverters overcome the shortcoming of conventional Er3+- doped upconverters that only a small portion of the solar spectrum at around 1.55 μm is utilized. If all the photons in the Er3+ absorption band ranging from 1.45 μm to 1.6 μm were perfectly upconverted, the improvement in the short-circuit current density (JSC) would be 1.9 mA/cm2 under the AM1.5G 1 sun solar illumination. The additional improvement for the broadband-sensitive upconverters developed here could be as high as 4.1 mA/cm2 by utilizing 1.1−1.45 μm photons, thus totally 6.1 mA/cm2. This corresponds to a significant gain in conversion efficiency (η) by 3.8% for c-Si solar cells with JSC = 40 mA/cm2 and η = 25%. The architecture of the broadband sensitization opens the door toward the concept of the third-generation solar cells with high conversion efficiency and low cost.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yasuhiko Takeda, Yasuhiko Takeda, Hom Nath Luitel, Hom Nath Luitel, Shintaro Mizuno, Shintaro Mizuno, Toshihiko Tani, Toshihiko Tani, "Broadband-sensitive upconverters co-doped with Er3+ and Ni2+ for crystalline silicon solar cells", Proc. SPIE 9937, Next Generation Technologies for Solar Energy Conversion VII, 99370E (23 September 2016); doi: 10.1117/12.2235502; https://doi.org/10.1117/12.2235502

Back to Top