Jin, Junyoung Park, Tae Hwan Lee, Kyeong-Seok Kim, Jaewook Park, Jongkil Seong, Tae-Yeon Hwang, Gyu Weon 2025-07-29T01:30:20Z 2025-07-29T01:30:20Z 2025-07-28 2025-08 0264-1275 https://pubs.kist.re.kr/handle/201004/152851 Lead chalcogenide quantum dot (QD) photodetectors have attracted considerable attention due to their high specific detectivity, process compatibility on Si circuitry enabling monolithic integration, adjustable bandgap in short-wavelength infrared (SWIR) range, and low fabrication cost. However, the narrow bandwidth of QD photoconductors, primarily caused by the traps on film surfaces limits the application of high-speed photodetection. Here, we introduced polymer capping layers-poly(perfluorobutenylvinylether) (CYTOP) and poly (methyl methacrylate) (PMMA)-on PbSe QD surfaces to suppress those trap states. The CYTOP-capped PbSe QD photoconductor device exhibited high specific detectivity (D*) of 3.34 x 1011 Jones at 3 kHz, responsivity of up to 4.22 A/W, and bandwidth of up to 67.1 kHz under a 2000-nm illumination, while the uncapped device showed low D* of 1.88 x 1010 Jones at 37.7 Hz. The additional analysis demonstrated that the high bandwidth was achieved by the improved carrier mobility and lifetime induced by the surface trap suppression. Our study paves the way for the development of fast-response quantum dot photodetectors with facile polymer capping. English Elsevier BV Bandwidth enhancement in SWIR QD photodetectors via interfacial trap suppression using polymer capping layers Article 10.1016/j.matdes.2025.114322 1 Materials & Design, v.256 Materials & Design 256 Y scie scopus 001527051000004 2-s2.0-105009459190 Materials Science, Multidisciplinary Materials Science Article FIELD-EFFECT TRANSISTORS CHARGE-TRANSPORT HIGH-MOBILITY QUANTUM PASSIVATION FILMS Lead selenide Quantum dots Bandwidth SWIR Polymer capping