Lim, Chanwoo Ha, Jung Min Kim, Nayoung Moon, Byung Joon Yu, Byoung-soo Hwang, Do Kyung Kim, Woong Woo, Han Young Yu, Hyeonggeun 2025-11-26T10:02:18Z 2025-11-26T10:02:18Z 2025-11-26 2026-01 https://pubs.kist.re.kr/handle/201004/153671 PbS colloidal quantum dots (CQDs) have attracted significant attention as next-generation infrared absorbers, offering a cost-effective alternative to conventional III–V compound semiconductors. Despite extensive efforts devoted to enhancing electron extraction, strategies for improving hole extraction at the metal-oxide/PbS CQD interface, particularly in inverted architectures, remain limited. Here, an effective interface engineering approach is reported using conjugated polyelectrolytes (CPEs) bearing ionic sidechains at the indium-tin oxide (ITO)/PbS CQD interface. By systematically increasing the ionic density within the CPEs, dark current and enhance photocurrent is simultaneously reduced, resulting in high near-infrared detectivity of 5.4 × 1012 Jones at 900 nm. These enhancements are attributed to favorable dipole orientation of the CPE at the interface, facilitating efficient hole extraction. Additionally, Br−ion functionalities in CPE sidechains provide effective surface passivation of PbS CQDs, increasing the device's built-in potential. This work highlights the importance of tailored CPE interlayers in achieving high-performance inverted PbS CQD photodiodes. English John Wiley and Sons Inc. Ionic Density-Controlled Conjugated Polyelectrolytes for Interface Engineering in Inverted Colloidal PbS Quantum-Dots Infrared Photodetector Article 10.1002/adom.202503023 1 Advanced Optical Materials, v.14, no.2 Advanced Optical Materials 14 2 Y scie scopus 001615576200001 2-s2.0-105022112152 Materials Science, Multidisciplinary Optics Materials Science Optics Article LIGAND-EXCHANGE SOLAR-CELLS THIN-FILMS MONODISPERSE EFFICIENCY BAND NANOCRYSTALS PASSIVATION STRATEGY ARRAY PbS quantum dots conjugated polyelectrolyte interface dipole inverted structure