Self-assembled monolayer-enhanced hole transport layers boost performance of PbS quantum dot photodetectors for CMOS compatibility
image: This image illustrates the improved performance of PbS quantum dot photodetectors with self-assembled monolayers (SAMs) as hole transport layers, demonstrating enhanced external quantum efficiency and specific detectivity for CMOS-compatible short-wave infrared imaging.
Credit: Nano Research, Shenzhen Technology University
A team of researchers from Shenzhen Technology University (SZTU) and Hubei University (HUBU) has made significant strides in enhancing the performance of PbS quantum dot (QD)-based short-wave infrared (SWIR) photodetectors by incorporating self-assembled monolayers (SAMs) into the hole transport layer (HTL) structure. This innovative approach addresses the challenges posed by traditional NiOx-based HTLs, which suffer from surface recombination due to their porous structure when annealed at low temperatures.
The introduction of SAMs, such as 2PACz and MeO-2PACz, has resulted in a dramatic improvement in device performance, with 2PACz achieving an external quantum efficiency (EQE) of 53% at 1200 nm, while MeO-2PACz successfully reduces dark current density to 220 nA/cm2, yielding a specific detectivity of 1.64 × 1012 Jones, setting a new benchmark in the field. This research offers a promising path forward for the development of high-performance, CMOS-compatible SWIR photodetectors.
Prof. Wei Chen, PI of the project, commented, “The integration of self-assembled monolayers into the hole transport layer not only enhances the efficiency and stability of PbS QD photodetectors but also ensures their compatibility with CMOS circuits, opening new possibilities for their use in a variety of imaging applications.”
The study was led by Haodong Tang, Zeguo Tang, Keyu Zheng, and Wei Chen, who emphasized the potential applications of this technology in fields such as night vision, and industrial quality control. These advancements pave the way for the widespread adoption of PbS QDs in real-world imaging applications, where high performance and CMOS compatibility are crucial.
Funding Sources:
This work was supported by the National Natural Science Foundation of China (No. 12204318), Shenzhen Science and Technology Program (Nos. RCYX20221008092908030, JCYJ20241202124709012), and the Natural Science Foundation of Top Talent of SZTU (Nos. GDRC202340, GDRC202345).
About the Authors
Dr. Haodong Tang is an Assistant professor in the College of Integrated Circuits and Optoelectronic Chips, Shenzhen Technology University, China. His research interests focus on the integration of solution processable semiconductor materials and related optoelectronic devices. Until now, He has published over 70 papers in Nature Electronics, Energy & Environmental Science, ACS Photonics and other journals. For more information, please pay attention to his research homepage https://hoooid.github.io/HaodongTangGroup/
Dr. Wei Chen is an Associate Professor in the College of Engineering Physics, Shenzhen Technology University, China. His research interests focus on nanostructure and optoelectronic property relationships and device applications of solution-processed semiconductor thin films, particularly on colloidal quantum dot detection and imaging technology. To date, he has published more than 100 papers in Nature Energy, Energy & Environmental Science, and other journals; presided over 5 national/provincial scientific research projects; and owns more than 30 invention patents. For more information, please visit his research homepages: https://chensztu.github.io (GitHub) and https://www.x-mol.com/groups/chenwei (X-Mol).
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.