Lin Jianjun, Wang Hongru, Zheng Yufan, Kan Yucheng, Chen Rui, Long Mingyue, Chen Ye, Zhou Zhiyong, Qi Ruijuan, Yue Fangyu, Duan Chun-Gang, Chu Junhao, Sun Lin
Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai, 200241, China.
Shanghai Institute of Ceramics, Key Laboratory of Inorganic Functional Materials and Devices, Chinese Academy of Sciences, Shanghai, 200050, China.
Adv Mater. 2025 Jan;37(4):e2414113. doi: 10.1002/adma.202414113. Epub 2024 Nov 26.
The bulk photovoltaic effect (BPVE), which uniquely exists in non-centrosymmetric materials, has been received extensive attention recently due to its potential to overcome the theoretical Shockley-Queisser limit in traditional p-n junction solar cells. Here, freestanding single-domain BiFeO membranes are exfoliated from miscut SrTiO substrates by dissolving SrAlO sacrificial layers, and transferred on SiO/Si substrates. This study finds that the freestanding BiFeO membranes maintain the single-domain structure and exhibits the significantly enhanced bulk photovoltaic response (≈200% enhancement), compared to the strained BiFeO films. The comprehensive atomic imaging analyses manifest that the freestanding BiFeO membrane demonstrates the bigger noncentral ion (Fe) displacement, which results in the larger in-plane ferroelectric polarization and substantial increase in the BPVE photocurrent. This work not only provides an effective approach to enhance the BPVE of ferroelectric oxide films, but also can potentially promote the exploration of BPVE of oxide membranes integrated with silicon-based or 2D electronics.
体光伏效应（BPVE）独特地存在于非中心对称材料中，由于其有潜力克服传统p-n结太阳能电池中的理论肖克利-奎塞尔极限，近来受到了广泛关注。在此，通过溶解SrAlO牺牲层，从错切的SrTiO衬底上剥离出独立的单畴BiFeO薄膜，并转移到SiO/Si衬底上。本研究发现，与应变BiFeO薄膜相比，独立的BiFeO薄膜保持了单畴结构，并表现出显著增强的体光伏响应（增强约200%）。综合原子成像分析表明，独立的BiFeO薄膜显示出更大的非中心离子（Fe）位移，这导致了更大的面内铁电极化和BPVE光电流的大幅增加。这项工作不仅提供了一种增强铁电氧化物薄膜BPVE的有效方法，而且还可能促进与硅基或二维电子器件集成的氧化物薄膜BPVE的探索。
