A Novel Approach for the Development of Moisture Encapsulation Poly(vinyl alcohol-co-ethylene) for Perovskite Solar Cells

Abstract

In this study, we developed the universal encapsulation method using poly(vinyl alcohol- co -ethylene) (EVOH) to improve the water stability of perovskite solar cells. In order to enhance the moisture barrier property, we utilized SiO 2 and graphene oxide (GO) fillers in the EVOH matrix. First, UV-treated SiO 2 increased the dispersibility in the EVOH matrix and made the penetrating path more complicated, which led to a better moisture barrier property. The water vapor transmission ratio (WVTR) is enhanced from 4.72 × 10 –2 (EVOH only) to 1.55 × 10 –2 (EVOH with SiO 2 filler) g/m 2 day. Second, we found that GO reduce the unreacted hydroxyl groups that could attract water molecules at the surface of EVOH. The addition of GO increased the WVTR up to 3.34 × 10 –3 g/m 2 day. Finally, our EVOH-based film successfully encapsulated without the efficiency drop. The encapsulated devices surprisingly maintained 86% of their performance even under direct contact with water for 5 h.

Inorganic Encapsulation Method Using Solution-Processible Polysilazane for Flexible Solar Cells

“…To investigate WVTR of the fabricated film, we coated the poly­(ethylene 2,6-naphthalenedicarboxylate) film (PEN, WVTR ∼ 4 g m –2 d –1 ) using the same fabrication method as was used for the Si substrate. The measured WVTR was determined to be 8.63 × 10 –3 g m −2 d –1 (37.8 °C/100 RH %), a satisfactory value for the printable encapsulant for PSCs. ,, …”

“…The measured WVTR was determined to be 8.63 × 10 −3 g m −2 d −1 (37.8 °C/100 RH %), a satisfactory value for the printable encapsulant for PSCs. 18,51,52 The initial efficiency of PSCs before the encapsulation was 16.8% (Figure 4a and Table S2). The highest efficiency was achieved with the QD-infused encapsulation, where the PCE reached 17.8% (Figure 4a and Table S3).…”

“…In the case of moisture barriers using inorganic materials, − their application requires high temperatures, which have a damaging effect on PSCs and put the cost and speed of the process at a disadvantage. Several research groups published on the deposition processes using organic materials that minimize the damage and help enhance the moisture barrier properties. − However, the usage of such processes is still challenging because of the high cost and poor processing speed. Organic materials tend to have a low water vapor transmission rate (WVTR) and cannot be utilized solely as an encapsulant.…”

Carbon nanomaterials–polymer composites for perovskite solar cells: preparation, properties and applications

“…5d). 127 SiO 2 nanoparticles (5 wt%) were added into EVOH to reduce the permeation of oxygen and water and introducing 1 wt% GO into EVOH/SiO 2 further decreased the water vapor transmission rate (WVTR). The EVOH–GO–SiO 2 encapsulation layer did not damage the efficiency of PSC devices, which showed a PCE of 17.86% with and 17.28% without the layer (Fig.…”

“…84 Copyright 2017, Royal Society of Chemistry. (d) Scheme of PSCs encapsulated with EVOH/S5/UV/G1, (e) efficiency of PSCs before and after encapsulation, and (f) reservoir test of PSCs encapsulated with EVOH/S5/UV/G1.Reproduced with permission 127. Copyright 2019, American Chemical Society.…”