Enhanced Water Vapor Blocking in Transparent Hybrid Polymer-Nanocrystal Films

Eun Seon Cho; Christopher M Evans; Emily C Davidson; Megan L Hoarfrost; Miguel A Modestino; Rachel A Segalman; Jeffrey J Urban

doi:10.1021/mz500765y

Enhanced Water Vapor Blocking in Transparent Hybrid Polymer-Nanocrystal Films

ACS Macro Lett. 2015 Jan 20;4(1):70-74. doi: 10.1021/mz500765y. Epub 2014 Dec 24.

Authors

Eun Seon Cho¹, Christopher M Evans², Emily C Davidson^{2

3}, Megan L Hoarfrost³, Miguel A Modestino³, Rachel A Segalman², Jeffrey J Urban¹

Affiliations

¹ The Molecular Foundry, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
² Departments of Chemical Engineering and Materials, University of California, Santa Barbara, Santa Barbara, California 93106, United States.
³ Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States.

PMID: 35596375
DOI: 10.1021/mz500765y

Abstract

Highly transparent and effective encapsulating materials have become increasingly important for photovoltaic (PV) modules to prevent water vapor molecules from permeating PV cells. The composite consists of block copolymer (PS-b-P2VP), comprised of hydrophobic and hydrophilic parts, and hygroscopic nanocrystals (Magnesium Oxide, MgO) incorporated to enhance water vapor blocking by both presenting obstacles for mass transport and also scavenging water molecules. The water vapor transmission rate (WVTR) values were reduced ∼3000 times, compared to homopolymer (PS), for both polymer and composite samples. Achieving both high transparency and low WVTR, it is expected that the composite materials can function as an excellent water vapor blocking layer for PV modules.