Unraveling Interfacial Photoinduced Charge Transfer and Localization in CsPbBr₃ Nanocrystals/Naphthalenediimide

Author(s)

Morais, Eliane A. ; Lemes, Maykon A. ; Souza, Natalilian R. S. ; Ito, Amando Siuiti ; Duarte, Evandro L. ; Silva, Ronaldo S. ; Brochsztain, Sergio ; Souza, Jose A.

• Document type: Journal article
• Source: ACS OMEGA; v. 9, n. 20, p. 9-pg., 2024-05-09.

Abstract

Halide perovskites have attracted much attention for energy conversion. However, efficient charge carrier generation, separation, and mobility remain the most important issues limiting the higher efficiency of solar cells. An efficient interfacial charge transfer process associated with exciton dynamics between all-inorganic CsPbBr3 nanocrystals and organic electron acceptors has been suggested. We observed a strong PL quenching of 78% in thin films when silane-functionalized naphthalenediimides (SNDI), used as electron-acceptors, are anchored on CsPbBr3 nanocrystals. Optical and structural characterizations confirm the charge transfer process without QDs degradation. The issue of whether these transferred charges are indeed available for utilization in solar cells remains uncertain. Our results reveal that the CsPbBr3 nanocrystals capped with these electron-acceptor SNDI molecules show a drastic increase in the electrical resistance and the absence of a photoconductivity effect. The results suggest charge transfer followed by strong localization of the charge carriers, preventing their extraction toward the electrodes of solar cell devices. We hope that this crucial aspect to attract attention and unveil a potential mechanism for charge delocalization, which could, in turn, lead to a groundbreaking enhancement in solar cell efficiency. (AU)

• FAPESP's process: 23/01316-3 - Magnetism in 2D halide perovskites towards magnetoelectric coupling and spintronics application
• Grantee: José Antonio Souza
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/10982-7 - Magnetism in 2D halide perovskites towards magnetoelectric coupling and spintronics application
• Grantee: Maykon Alves Lemes
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• FAPESP's process: 21/14422-0 - Computational design of stable halide perovskites: effects of defects, alloys, and pressure
• Grantee: Gustavo Martini Dalpian
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants