Enhanced photoluminescence quantum yield of MAPbBr3 nanocrystals by passivation using graphene

• Published in: Nano research Vol. 13; no. 4; pp. 932 - 938
• Main Authors: Park, Youngsin, Jana, Atanu, Myung, Chang Woo, Yoon, Taeseung, Lee, Geungsik, Kocher, Claudius C., Ying, Guanhua, Osokin, Vitaly, Taylor, Robert A., Kim, Kwang S.
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.04.2020
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Chemistry and Materials Science; Condensed Matter Physics; Crystals; Density functional theory; Diameters; Encapsulation; Graphene; Lead compounds; Luminescence; Materials Science; Metal halides; Nanocrystals; Nanotechnology; Optical properties; Optoelectronic devices; Perovskites; Photoluminescence; Photons; Research Article; Restoration; Surface defects; Temperature dependence; Time dependence; surface passivation; density functional theory calculations; photoluminescence; graphene; perovskite nanocluster
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-020-2718-8

Diminishing surface defect states in perovskite nanocrystals is a highly challenging subject for enhancing optoelectronic device performance. We synthesized organic/inorganic lead-halide perovskite MAPbBr 3 (MA = methylammonium) clusters comprising nanocrystals with diameters ranging between 20–30 nm and characterized an enhanced photoluminescence (PL) quantum yield (as much as ~ 7 times) by encapsulating the MAPbBr 3 with graphene (Gr). The optical properties of MAPbBr 3 and Gr/MAPbBr 3 were investigated by temperature-dependent micro-PL and time-resolved PL measurements. Density functional theory calculations show that the surface defect states in MAPbBr 3 are removed and the optical band gap is reduced by a 0.15 eV by encapsulation with graphene due to partial restoration of lattice distortions.