Multiferroic Double Perovskites ScFe1-xCrxO3 (1/6 ≤ x ≤ 5/6) for Highly Efficient Photovoltaics and Spintronics

作者：Cai, Tian-Yi; Liu, Shi-Chen; Ju, Sheng^*; Liu, Cheng-You; Guo, Guang-Yu

来源：Physical Review Applied, 2017, 8(3): 034034.

DOI：10.1103/PhysRevApplied.8.034034

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Ferroelectric oxides are attractive materials for constructing efficient solar cells. Nevertheless, a wide band gap of nearly 3.0 eV in these ferroelectric oxides would result in poor overall sunlight absorption and, hence, low energy conversion efficiency. Here, by systematic first-principles density-functional calculations, we demonstrate that double-perovskite semiconductors ScFe1-xCrxO3(1/6 <= x <= 5/6) with a narrow band gap of approximately 1.8 eV would simultaneously exhibit large ferroelectric polarization (100 mu C/cm(2)) and ferrimagnetic magnetization (170 emu/cm(3)). Within a Schottky-based model for a typical sandwich solar-cell structure, a power-conversion efficiency of 9.0% can be reached by neglecting all other sources of photovoltaicity in ferroelectric materials. This value is larger than the largest value of 8.1% observed in ferroelectric oxides. Furthermore, these double perovskites are found to be single-spin semiconductors, and the obtained photocurrent is fully spin polarized over almost the entire Sun spectrum. These fascinating advantages would make ScFexCr1-xO3(1/6 <= x <= 5/6) semiconductors promising candidates for highly efficient solar cells and spin photovoltaic devices.

• 出版日期2017-9-28
• 单位苏州大学