Nanophotonic structures energized short-wave infrared quantum dot photodetectors and their advancements in imaging and large-scale fabrication techniques

Short-wave infrared (SWIR) photodetectors (PDs) have a wide range of applications in the field of information and communication. Especially in recent years, with the increasing demand for consumer electronics, conventional semiconductor-based PDs alone are unable to cope with the ever-increasing market. Colloidal quantum dots (QDs) have attracted great interest due to their low fabrication cost, solution processability, and promising optoelectronic properties. In addition to advancements in synthesis methods and surface ligand engineering, the photoelectronic performance of QD-based SWIR PDs has been greatly improved due to developments in nanophotonic structural engineering, such as microcavities, localized and propagating surface plasmon resonant structures, and gratings for specific and high-performance detection application. The improvement in the performance of photoconductors, photodiodes, and phototransistors also enhances the performance of SWIR imaging sensors where they have been realized and demonstrated promising potential due to the direct integration of QD PDs with CMOS substrates. In addition, flexible manipulation of the QDs has been realized, thanks to their solution-processable capability. Therefore, a variety of large-scale production process methods have been examined including blade coating, flexible microcomb printing, ink-jet printing, spray deposition, etc. which can effectively reduce the cost and promote commercial application in consumer electronics. Finally, the current challenges and future development prospects of QD-based PDs are reviewed and could provide guidance for future design of the QDs PDs.