Namhee Kwon Song, Seung Ho Jin, Junyoung Kim, Seunghwan Kim, Kitae Hwang, Gyu Weon Yi, Yeonjin Oh, Soong Ju Koch, Norbert Kim, Yong-Hoon Hwang, Do Kyung Park, Soohyung 2024-05-27T05:30:05Z 2024-05-27T05:30:05Z 2024-05-24 2024-08 0169-4332 https://pubs.kist.re.kr/handle/201004/149922 PbS quantum dots capped by ethanedithiol (PbS QD-EDT) and tetrabutylammonium iodide (PbS QD-TBAI) and supported by different substrates were examined in terms of Fermi level pinning (FLP), gap states, and electron and hole barriers (Φe and Φh, respectively) using ultraviolet and low-energy inverse photoemission spectroscopy. The former analysis showed that TBAI and EDT differed in their ability to induce gap-state passivation, with the corresponding energy difference determined as 4.0 eV. Two FLP regimes were identified: at substrate work function (Фsub) < 4.0 eV, both ligands showed perfect FLP (S ？ 0 for holes and electrons), whereas at Фsub > 4.0 eV, the pinning strength of PbS QD-EDT (S of Фb,h and Фb,e = 0.19 and 0.24, respectively) exceeded that of PbS QD-TBAI (S of Фb,h and Фb,e = 0.53 and 0.57, respectively). Thus, the gap states were more effectively passivated in the case of PbS QD-TBAI. Our results indicate the importance of considering FLP strength when working with high-work-function substrates for the design of optimized QD-based devices. English Elsevier BV The influence of ligands passivation on strength of Fermi level pinning in the quantum dots interface Article 10.1016/j.apsusc.2024.160235 1 Applied Surface Science, v.664 Applied Surface Science 664 Y scie scopus 001243493900001 Chemistry, Physical Materials Science, Coatings & Films Physics, Applied Physics, Condensed Matter Chemistry Materials Science Physics Article STATES PHOTOTRANSISTORS TRANSITION VALENCE GAP SOLAR-CELLS GRAPHENE Low-energy inverse photoemission spectroscopy PbS quantum dot Gap state Fermi level pinning Energy level alignment Photoemission spectroscopy