文章基本信息

标题：New high T_c multiferroics KBiFe₂O₅ with narrow band gap and promising photovoltaic effect
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作者：Ganghua Zhang ; Hui Wu ; Guobao Li 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2013
卷号：3
DOI：10.1038/srep01265
出版社：Springer Nature
摘要：Intrinsic polarization of ferroelectrics (FE) helps separate photon-generated charge carriers thus enhances photovoltaic effects. However, traditional FE with transition-metal cations ( M ) of d ⁰ electron in M O₆ network typically has a band gap ( E _g) exceeding 3.0 eV. Although a smaller E _g (2.6 eV) can be obtained in multiferroic BiFeO₃, the value is still too high for optimal solar energy applications. Computational “materials genome” searches have predicted several exotic M O₆ FE with E _g M O₄ tetrahedral network, KBiFe₂O₅, which features narrow E _g (1.6 eV), high Curie temperature ( T _c ~ 780 K) and robust magnetic and photoelectric activities. The high photovoltage (8.8 V) and photocurrent density (15 μA/cm²) were obtained, which is comparable to the reported BiFeO₃. This finding may open a new avenue to discovering and designing optimal FE compounds for solar energy applications.