Liao Gengcheng, Qin Jinghan, Ren Long, Ren Zhizhen, Xie Jing, Cui Dandan, Cheng Ningyan, Han Wei, Du Yi, Qi Xiang
Hunan Key Laboratory of Micro-Nano Energy Materials and Devices and School of Physics and Optoelectronics, Xiangtan University, Hunan 411105, P. R. China.
School of Physics, Beihang University, Beijing 100191, P. R. China.
ACS Appl Mater Interfaces. 2025 Jul 30;17(30):43808-43819. doi: 10.1021/acsami.5c08703. Epub 2025 Jul 17.
Inspired by the hierarchical micro/nanoscale architecture of diatoms which are renown for capturing and utilizing dim light in oceanic environments, a three-dimensional (3D) hierarchical liquid metal (LM) sponge was proposed for advancing flexible photoelectrochemical (PEC) photodetectors. A room-temperature LM nanodroplet (ND)-bridging strategy by deformable welding LM NDs on polymer fibers was developed to controllably fabricate 3D architectures consisting of LM integrations in the form of interconnected either one-dimensional (1D) liquid-bridges or two-dimensional (2D) liquid-films. Optical characterization reveals that the 3D hierarchical architecture with radian 2D liquid-films (3D-HA-R2DLF) exhibits moderate absorption (0.34), enhanced reflection (0.55), and minimal transmission (0.01) at 500 nm, with light scattering extending the optical path length for improved photon utilization. Carrier dynamics analysis demonstrates its optimal performance: a carrier concentration of 9.79 × 10 m and mobility of 9.31 × 10 cm/V·s, outperforming 1D-liquid-bridges (high mobility but low concentration) and the 3D hierarchical architecture with flat 2D liquid-films (3D-HA-F2DLF) (high concentration but mobility-limited scattering). This 3D architecture combines conductive LM for charge transport with semiconductive amorphous gallium oxide (GaO) layers for photoabsorption/conversion, achieving the efficient light energy utilization similar to that done by diatoms' microstructure. Specifically, the 3D LM sponge consisting of radian 2D liquid-films achieved a photocurrent density of 1.99 μA/cm, 3.1 times and 9.47 times higher than its counterparts with flat 2D liquid-films and 1D-liquid-bridges, respectively. Additionally, it exhibited faster response times (0.19 s for response; 0.13 s for recovery). The photodetector demonstrated excellent stability over 4000 s of continuous use and 4000 bending cycles, highlighting its robustness. The concept by bridging LM-NDs into 3D hierarchical and heterogeneous architectures offers a promising strategy to integrating LMs and semiconductors into functional devices, particularly for flexible photoelectric-devices.
受硅藻的分级微/纳米级结构启发，这种结构因在海洋环境中捕获和利用微弱光线而闻名，人们提出了一种三维（3D）分级液态金属（LM）海绵，以推进柔性光电化学（PEC）光电探测器的发展。开发了一种室温LM纳米液滴（ND）桥接策略，通过在聚合物纤维上对LM ND进行可变形焊接，可控地制造出由以相互连接的一维（1D）液桥或二维（2D）液膜形式存在的LM集成体组成的3D结构。光学表征表明，具有弧度2D液膜的3D分级结构（3D-HA-R2DLF）在500 nm处表现出适度的吸收（0.34）、增强的反射（0.55）和最小的透射（0.01），光散射延长了光程长度以提高光子利用率。载流子动力学分析证明了其最佳性能：载流子浓度为9.79×10 m，迁移率为9.31×10 cm²/V·s，优于1D液桥（高迁移率但低浓度）和具有平坦2D液膜的3D分级结构（3D-HA-F2DLF）（高浓度但迁移率受限于散射）。这种3D结构将用于电荷传输的导电LM与用于光吸收/转换的半导体非晶氧化镓（Ga₂O₃）层相结合，实现了与硅藻微观结构类似的高效光能利用。具体而言，由弧度2D液膜组成的3D LM海绵实现的光电流密度为1.99 μA/cm²，分别比具有平坦2D液膜和1D液桥的同类产品高3.1倍和9.47倍。此外，它表现出更快的响应时间（响应时间为0.19 s；恢复时间为0.13 s）。该光电探测器在连续使用4000 s和4000次弯曲循环中表现出优异的稳定性，突出了其坚固性。通过将LM-ND桥接成3D分级和异质结构的概念为将LM和半导体集成到功能器件中提供了一种有前景的策略，特别是对于柔性光电器件。
