Zhao Xinyu, Song Li, Zhao Rong, Tan Mei Chee
Engineering Product Development , Singapore University of Technology and Design , 8 Somapah Road , Singapore 487372 , Singapore.
ACS Appl Mater Interfaces. 2019 Jan 16;11(2):2344-2351. doi: 10.1021/acsami.8b16978. Epub 2019 Jan 4.
The growing demand of infrared sensors for emerging applications such as autonomous vehicles and remote control and sensing systems has driven the development of flexible, low-power, and sensitive infrared detectors for seamless product integration. Although semiconducting polymer (SCP)-based photodetectors are promising solutions, challenges in synthesis chemistry and high thermal dark currents associated with narrowing of band gaps have limited their progress. To address these challenges, we have designed a new class of composites comprising SCPs with moderate band gap and rare earth doped-nanoparticles (RENPs) that enable photon-to-electron conversion beyond the SCP's response range. Using this RENP-SCP (RE-SCP) composite, we demonstrated detection at multiple wavelengths (808, 975, and 1532 nm) for planar-type photodetectors. Notably, the RE-SCP composite-based device detected an eye-safe, shortwave infrared (SWIR) source at 1532 nm with high SWIR responsivity of 0.02 A/W and an SWIR external quantum efficiency of 2%. The key attribute governing the excellent SWIR responsivity and sensitivity was the distinctive SWIR upconversion characteristic of RENPs that extended and improved the SCP's detection range and performance, respectively. Additionally, the absence of significant performance degradation of the SWIR photodetector for bending curvatures from 0-0.67 cm highlights the promise of our RE-SCP composite-based flexible SWIR photodetectors.
对自动驾驶汽车以及遥控与传感系统等新兴应用中红外传感器日益增长的需求，推动了用于无缝产品集成的柔性、低功耗且灵敏的红外探测器的发展。尽管基于半导体聚合物（SCP）的光电探测器是很有前景的解决方案，但合成化学方面的挑战以及与带隙变窄相关的高热暗电流限制了它们的进展。为应对这些挑战，我们设计了一类新型复合材料，其由具有适度带隙的SCP和稀土掺杂纳米颗粒（RENP）组成，能实现超出SCP响应范围的光子到电子的转换。使用这种RENP - SCP（RE - SCP）复合材料，我们展示了平面型光电探测器在多个波长（808、975和1532 nm）下的探测能力。值得注意的是，基于RE - SCP复合材料的器件在1532 nm处检测到一个对眼睛安全的短波红外（SWIR）源，具有0.02 A/W的高SWIR响应度和2%的SWIR外量子效率。决定出色的SWIR响应度和灵敏度的关键特性是RENP独特的SWIR上转换特性，它分别扩展并改善了SCP的探测范围和性能。此外，对于0 - 0.67 cm的弯曲曲率，SWIR光电探测器没有明显的性能退化，这突出了我们基于RE - SCP复合材料的柔性SWIR光电探测器的前景。
