Chakrabartty Joyprokash, Nechache Riad, Harnagea Catalin, Li Shun, Rosei Federico
Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique (INRS), 1650 boulevard Lionel-Boulet, Varennes, Québec J3X 1S2, Canada.
Nanotechnology. 2016 May 27;27(21):215402. doi: 10.1088/0957-4484/27/21/215402. Epub 2016 Apr 20.
We report an external solar power conversion efficiency of ∼1.43% in BiFeO3(BFO)/BiMnO3(BMO) bilayer thin films. Both films are epitaxially grown on (111) oriented niobium doped SrTiO3 (NSTO) single crystal substrates by pulsed laser deposition. By illuminating the BFO/BMO films under 1 Sun (AM 1.5 G), we found a remarkably high fill factor of ∼0.72, much higher than values reported for devices based on BFO or BMO alone. In addition, we demonstrate that the photocurrent density and photovoltage are tunable by changing the polarization direction in the BFO/BMO bilayer, as confirmed by the macroscopic polarization-voltage (P-V) hysteresis loop. This effect is described in terms of a more favorable energy band alignment of the electrode/bilayer/NSTO heterostructure junction, which controls photocarrier separation.
我们报道了BiFeO₃（BFO）/BiMnO₃（BMO）双层薄膜的外部太阳能转换效率约为1.43%。这两种薄膜均通过脉冲激光沉积在（111）取向的掺铌SrTiO₃（NSTO）单晶衬底上外延生长。通过在1个太阳（AM 1.5 G）光照下照射BFO/BMO薄膜，我们发现其填充因子高达约0.72，远高于仅基于BFO或BMO的器件所报道的值。此外，正如宏观极化 - 电压（P - V）滞后回线所证实的那样，我们证明了通过改变BFO/BMO双层中的极化方向可以调节光电流密度和光电压。这种效应可以通过电极/双层/NSTO异质结构结更有利的能带排列来描述，该排列控制光载流子的分离。
