TY - JOUR
T1 - Synergistic Hybrid-Ligand Passivation of Perovskite Quantum Dots
T2 - Suppressing Reduced-Dimensionality and Enhancing Optoelectronic Performance
AU - Han, Sanghun
AU - Jeong, Woo Hyeon
AU - Seo, Gayoung
AU - Choi, Seongmin
AU - Lee, Dong Gyu
AU - Chae, Weon Sik
AU - Ahn, Hyungju
AU - Lee, Tae Kyung
AU - Choi, Hyosung
AU - Choi, Jongmin
AU - Lee, Bo Ram
AU - Kim, Younghoon
N1 - Publisher Copyright:
© 2025 Wiley-VCH GmbH.
PY - 2025
Y1 - 2025
N2 - In terms of surface passivation for realizing efficient CsPbI3-perovskite quantum dot (CsPbI3-PQD)-based optoelectronic devices, phenethylammonium iodide (PEAI) is widely used during the ligand exchange. However, the PEA cation, due to its large ionic radius incompatible with the 3D perovskite framework, acts as an organic spacer within polycrystalline perovskites, leading to the formation of reduced dimensional perovskites (RDPs). Despite sharing the identical 3D perovskite framework, the influence of PEAI on the structure of CsPbI3-PQDs remains unexplored. Here, it is revealed that PEAI can induce the formation of high-n RDPs (n > 2) within the CsPbI3-PQD solids, but these high-n RDPs undergo an undesirable phase transition to low-n RDPs, leading to the structural and optical degradation of CsPbI3-PQDs. To address the PEAI-induced issue, we employ triphenylphosphine oxide (TPPO) as an ancillary ligand during the ligand exchange process. The incorporation of TPPO prevents H2O penetration and regulates the rapid diffusion of PEAI, suppressing the formation of low-n RDPs. Moreover, TPPO can passivate the uncoordinated Pb2+ sites, reducing the nonradiative recombination. This hybrid-ligand exchange strategy using both PEAI and TPPO enables realizing efficient and stable CsPbI3-PQD-based light-emitting diode (external quantum efficiency of 21.8%) and solar cell (power conversion efficiency of 15.3%) devices.
AB - In terms of surface passivation for realizing efficient CsPbI3-perovskite quantum dot (CsPbI3-PQD)-based optoelectronic devices, phenethylammonium iodide (PEAI) is widely used during the ligand exchange. However, the PEA cation, due to its large ionic radius incompatible with the 3D perovskite framework, acts as an organic spacer within polycrystalline perovskites, leading to the formation of reduced dimensional perovskites (RDPs). Despite sharing the identical 3D perovskite framework, the influence of PEAI on the structure of CsPbI3-PQDs remains unexplored. Here, it is revealed that PEAI can induce the formation of high-n RDPs (n > 2) within the CsPbI3-PQD solids, but these high-n RDPs undergo an undesirable phase transition to low-n RDPs, leading to the structural and optical degradation of CsPbI3-PQDs. To address the PEAI-induced issue, we employ triphenylphosphine oxide (TPPO) as an ancillary ligand during the ligand exchange process. The incorporation of TPPO prevents H2O penetration and regulates the rapid diffusion of PEAI, suppressing the formation of low-n RDPs. Moreover, TPPO can passivate the uncoordinated Pb2+ sites, reducing the nonradiative recombination. This hybrid-ligand exchange strategy using both PEAI and TPPO enables realizing efficient and stable CsPbI3-PQD-based light-emitting diode (external quantum efficiency of 21.8%) and solar cell (power conversion efficiency of 15.3%) devices.
KW - all-inorganic CsPbI
KW - ligand exchanges
KW - light-emitting diodes
KW - perovskite quantum dots
KW - reduced dimensional perovskites
KW - solar cells
UR - http://www.scopus.com/inward/record.url?scp=85216431137&partnerID=8YFLogxK
U2 - 10.1002/adma.202410128
DO - 10.1002/adma.202410128
M3 - Article
AN - SCOPUS:85216431137
SN - 0935-9648
JO - Advanced Materials
JF - Advanced Materials
ER -