Effect of out-gassing from polymeric encapsulant materials on the lifetime of perovskite solar cells

Rational Design, Synthesis, and Structure–Property Relationship Studies of a Library of Thermoplastic Polyurethane Films as an Effective and Scalable Encapsulation Material for Perovskite Solar Cells

“…We also studied the interaction of the encapsulated absorber film with water, and for this we dipped the encapsulated absorbers and kept them under water for 48 h (Figure S47). As can be seen from the digital photograph, no significant color change in the film was observed, and this reveals that the encapsulated absorber is intact even after completely drenched in water for 48 h, whereas the unencapsulated absorber film turned completely yellow (indicating the transformation to lead iodide) within 3–5 s. This test also confirms that both PU1 and PU2 adhere well with the glass substrate without leaving any space for water molecules to permeate into the perovskite absorber films unlike epoxy-based glues which shows water permeation over time . The absorption and PL studies, together with the photographs, confirm that the synthesized PUs can protect the absorber films even under extreme humid conditions.…”

“…As can be seen from the digital photograph, no significant color change in the film was observed, and this reveals that the encapsulated absorber is intact even after completely drenched in water for 48 h, whereas the This test also confirms that both PU1 and PU2 adhere well with the glass substrate without leaving any space for water molecules to permeate into the perovskite absorber films unlike epoxy-based glues which shows water permeation over time. 35 The absorption and PL studies, together with the photographs, confirm that the synthesized PUs can protect the absorber films even under extreme humid conditions. This is primarily due to their low WVTR values (PU1�9.68 g m −2 day −1 ; PU2�6.98 g m −2 day −1 ).…”

“…12,13,34 The traditional encapsulant EVA which is routinely used in silicon solar cell technology suffers from optical degradation such as yellowing, which is triggered by acetic acid formation, thereby easily damaging the perovskite absorber and electrodes and hence is not practical to use in PSCs. 23,31 Other encapsulants like epoxy and polyisobutylene (PIB) suffer from the release of moisture through outgassing 35 and transparency issues, respectively, thus limiting its use in PSCs. 36 As can be seen from the above examples, selecting a robust hermetic encapsulant for PSCs is far more stringent compared to the silicon solar cell technology.…”

“…Materials like glass frit, , metal oxides (Al 2 O 3 ), − and multilayered barriers − and polymers like ethylene-vinyl acetate (EVA), , epoxy, , poly­(methyl methacrylate) (PMMA), , PET, , polyolefins, and paraffin , have been employed earlier for PSCs to improve their device lifetime. There are several published reviews focused on encapsulation materials, encapsulation strategies, and barrier design. ,, The traditional encapsulant EVA which is routinely used in silicon solar cell technology suffers from optical degradation such as yellowing, which is triggered by acetic acid formation, thereby easily damaging the perovskite absorber and electrodes and hence is not practical to use in PSCs. , Other encapsulants like epoxy and polyisobutylene (PIB) suffer from the release of moisture through outgassing and transparency issues, respectively, thus limiting its use in PSCs . As can be seen from the above examples, selecting a robust hermetic encapsulant for PSCs is far more stringent compared to the silicon solar cell technology.…”

Vacuum‐Free and Solvent‐Free Deposition of Electrodes for Roll‐to‐Roll Fabricated Perovskite Solar Cells

“…[ 28 ] The PSCs and barrier materials were all appropriately preconditioned prior to encapsulation to mitigate the risk of moisture and oxygen outgassing. [ 29 ] The encapsulation architecture is illustrated in Figure 4 a. A 200 nm thick Ag pattern was evaporated onto the back‐barrier film to enable electrical contact with the device.…”