Hou Xinyi, Kong Fanyi, Tong Yunhao, Li Haoran, Dai Jianxun, Li Yongjiang, Huang Huolin, Sun Changsen, Gao Junfeng, Pan Lujun, Li Dawei
School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning, 116024, China.
School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian, Liaoning, 116024, China.
Small. 2025 Feb;21(5):e2409879. doi: 10.1002/smll.202409879. Epub 2024 Dec 17.
The precise domain control in ferroelectric CuInPS (CIPS) remains challenging. A promising approach is by interfacing CIPS with the ferroelectric layer, but interface-driven ferroelectricity tunning mechanism remains unclear. Here, the demonstration of interfacial strain-induced ferroelectric tuning and enhancement in CIPS via ferroelectric substrate is reported by photoluminescence (PL) spectroscopy, combined with piezoresponse force microscopy (PFM) and density functional theory (DFT) calculations. PFM studies show that thin CIPS flakes form the same domain as that of ferroelectric PbZrTiO (PZT) and P(VDF-TrFE) films, suggesting enhanced polar alignment in CIPS via ferroelectric substrate. PL analyses show that a significant redshift occurs for PL emission of CIPS on ferroelectric substrate compared with that on conventional substrate, revealing interface tensile strain-induced lattice change in CIPS, as further confirmed by DFT calculation. By analyzing PL spectra of monolayer MoS on CIPS/PZT, the polarization of CIPS is evidenced to be anti-aligned with that of ferroelectric substrate. In situ, temperature-dependent PL studies show that thin CIPS on ferroelectric substrate exhibits enhanced Curie temperature of higher than 200 °C. This study not only provides an effective material strategy to engineer the ferroelectric properties of CIPS but also offers a simple optical method to reveal interface-driven ferroelectricity modulation mechanism in CIPS.
铁电体CuInPS（CIPS）中的精确畴控制仍然具有挑战性。一种很有前景的方法是将CIPS与铁电层相结合，但界面驱动的铁电调谐机制仍不清楚。在此，通过光致发光（PL）光谱，并结合压电响应力显微镜（PFM）和密度泛函理论（DFT）计算，报道了通过铁电衬底在CIPS中实现界面应变诱导的铁电调谐和增强。PFM研究表明，CIPS薄片形成了与铁电体PbZrTiO（PZT）和P（VDF-TrFE）薄膜相同的畴，这表明通过铁电衬底CIPS中的极性排列得到了增强。PL分析表明，与传统衬底上的CIPS相比，铁电衬底上的CIPS的PL发射发生了显著的红移，揭示了界面拉伸应变诱导的CIPS晶格变化，DFT计算进一步证实了这一点。通过分析CIPS/PZT上单层MoS的PL光谱，证明了CIPS的极化与铁电衬底的极化反平行。原位温度相关的PL研究表明，铁电衬底上的CIPS薄膜表现出高于200°C的增强居里温度。这项研究不仅提供了一种有效的材料策略来调控CIPS的铁电性能，还提供了一种简单的光学方法来揭示CIPS中界面驱动的铁电调制机制。
