Advanced Functional Materials:在柔性红外光体积描记术(PPG)脉搏探测研究应用新进展

柔性光电探测在生物传感/检测、可穿戴和个性化实时健康监测等领域中有广泛的应用。其中人体心率及波形的实时监控是各类诊断中必不可少的重要生理信号。针对此需求,南京大学余林蔚教授课题组探索将三维架构的径向结非晶硅锗薄膜(3D a-SiGe:H p-i-n radial junction)光电器件应用于人体脉搏探测。首次基于铝箔上直接生长的超柔性径向结光电探测单元,于手腕处成功实现了对脉搏信号的光体积描记术(PPG)检测(探测光@800 nm)。区别于通常的血氧技术,该技术能直接探测由于动脉血容量变化而导致的血管变化(而不是基于血氧浓度变化),故而可以更精确地提取关键心跳信息,有望发展成为更舒适、更精确的人体实时脉搏监测技术。

图1. 径向结红外光电探测器的制备流程以及脉搏信号探测示意图

此工作基于课题组硅基径向结薄膜光电器件的系列研究工作(见附录),其中纳米线结构通过低温<350 °C “气-液-固”(VLS)技术直接生长在铝箔之上。由于硅纳米线在“软”的铝箔表面所形成稳固的锚(anchor)接触,对保护表面淀积薄膜的完整性起到了关键的稳定作用,避免了薄膜在受力时发生剥离、破裂、脱落,可以在力学特性不稳定的“软”铝箔基底上构建高品质、性能稳定的光电器件。进一步研究分析发现:径向结所承受的应力主要集中在径向结根部与平面部分,比径向结顶部所承受的应力要大3~4个数量级。得益于3D硅米线架构,该器件即使弯曲1000次(弯曲半径为10 mm)后,仍具有~140 mA/W@800 nm的响应度及超快的响应速率tr=5.4 μs, tf=17.6 μs (弯折前为3.6 μs/13.2 μs)。

图2. 径向结表面所承受应力分析

南京大学电子科学与工程学院博士生张少波同学为论文的第一作者,余林蔚教授、刘宗光副研究员为论文共同通讯作者。相关工作得到了电子科学与工程学院的徐骏教授、施毅教授、陈坤基教授的大力支持,以及国家自然科学基金项目支持,在此一并表示衷心感谢!

课题组相关前期工作:

1. Highly flexible radial tandem junction thin film solar cells with excellent power-to-weight ratio

Shaobo Zhang, Ting Zhang, Zongguang Liu, Junzhuan Wang*, Linwei Yu*, Jun Xu, Kunji Chen, Pere Roca i Cabarrocas

Nano Energy 86 (2021) 106121

2. Coupled boron-doping and geometry control of tin-catalyzed silicon nanowires for high performance radial junction photovoltaics

Shaobo Zhang, Ting Zhang, Luyao Cao, Zongguang Liu*, Junzhuan Wang, Jun Xu, Kunji Chen, Linwei Yu*

Optics Express 27 (2019) 37248-37256

3. Nanoscale photovoltaic responses in 3D radial junction solar cells revealed by high spatial resolution laser excitation photoelectric microscopy

Huili Zhang#, Yakui Lei#, Qiang Zhu, Tong Qing, Ting Zhang, Wanghao Tian, Matthias Lange, Meiping Jiang, Chao Han, Jun Li, Dieter Koelle, Reinhold Kleiner, Wei-Wei Xu, Yonglei Wang, Linwei Yu*, Huabing Wang*, Peiheng Wu

ACS Nano 13, 10359-10365 (2019)

4. Firmly standing three-dimensional radial junctions on soft aluminum foils enable extremely low cost flexible thin film solar cells with very high power-to-weight performance

Xiaolin Sun, Ting Zhang,Junzhuan Wang*, Fan Yang, Ling Xu, Jun Xu, Yi Shi, Kunji Chen, Pere Roca i Cabarrocas, Linwei Yu*

Nano Energy 53 (2018)83-90

5. Ultra-fast solar-blind ultraviolet detection by inorganic perovskite CsPbX3 quantum dots radial junction architecture

Jiawen Lu, Xuexi Sheng, Guoqing Tong, Zhongwei Yu, Xiaolin Sun, Linwei Yu*, Xiangxin Xu*, Junzhuan Wang, Jun Xu, Yi Shi, and Kunji Chen

Advanced Materials 29 (2017) 1700400

论文信息:

Flexible and Robust 3D a-SiGe Radial Junction Near-Infrared Photodetectors for Rapid Sphygmic Signal Monitoring

Shaobo Zhang, Ting Zhang, Zongguang Liu*, Junzhuan Wang, Jun Xu, Kunji Chen, Linwei Yu*

Advanced Functional Materials

DOI: 10.1002/adfm.202107040

文章链接:https://onlinelibrary.wiley.com/doi/10.1002/adfm.202107040