title: Encapsulation of Perovskite Nanocrystals into Macroscale Polymer Matrices: Enhanced Stability and Polarization.
abstract: Lead halide perovskites hold promise for photonic devices, due to their superior optoelectronic properties. However, their use is limited by poor stability and toxicity. We demonstrate enhanced water and light stability of high-surface-area colloidal perovskite nanocrystals by encapsulation of colloidal CsPbBr3quantum dots into matched hydrophobic macroscale polymeric matrices. This is achieved by mixing the quantum dots with presynthesized high-molecular-weight polymers. We monitor the photoluminescence quantum yield of the perovskite-polymer nanocomposite films under water-soaking for the first time, finding no change even after >4 months of continuous immersion in water. Furthermore, photostability is greatly enhanced in the macroscale polymer-encapsulated nanocrystal perovskites, which sustain >1010absorption events per quantum dot prior to photodegradation, a significant threshold for potential device use. Control of the quantum dot shape in these thin-film polymer composite enables color tunability via strong quantum-confinement in nanoplates and significant room temperature polarized emission from perovskite nanowires. Not only does the high-molecular-weight polymer protect the perovskites from the environment but also no escaped lead was detected in water that was in contact with the encapsulated perovskites for months. Our ligand-passivated perovskite-macroscale polymer composites provide a robust platform for diverse photonic applications.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Shilpa N
authors.identifier: http://orcid.org/0000-0001-5641-8930
authors.initials: SN
authors.lastname: Raja
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy NanoScience Institute , Berkeley, California 94720, United States.
authors.forename: Yehonadav
authors.initials: Y
authors.lastname: Bekenstein
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Matthew A
authors.identifier: http://orcid.org/0000-0003-1401-8415
authors.initials: MA
authors.lastname: Koc
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fischer
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhang
authors.forename: Liwei
authors.initials: L
authors.lastname: Lin
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Robert O
authors.identifier: http://orcid.org/0000-0002-0501-6998
authors.initials: RO
authors.lastname: Ritchie
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy NanoScience Institute , Berkeley, California 94720, United States.
authors.forename: Peidong
authors.initials: P
authors.lastname: Yang
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy NanoScience Institute , Berkeley, California 94720, United States.
authors.forename: A Paul
authors.initials: AP
authors.lastname: Alivisatos
keywords: hydrophobic polymer; light and water stability; nanocomposite polarization; nanowires and nanoplates; perovskite quantum dot nanocrystals; photon budget