Efficiency and stability enhancement of organic-inorganic perovskite solar cells through micropatterned Norland Optical Adhesive and polyethylene terephthalate encapsulation

We investigated the enhancement of the power conversion efficiency (PCE) and moisture stability of perovskite solar cells (PSCs). For this, we fabricated Norland Optical Adhesive (NOA) layers on polyethylene terephthalate (PET) films. We created micropatterns on the NOA layer surface by nanoimprinting. The micropatterns not only decreased light reflection but also increased the surface hydrophobicity. The reflectance of micropatterned NOA was decreased by 44.6% compared to that of flat NOA. In addition, the PCE of (FAPbI(3))(0.85) (MAPbBr(3))(0.)(15)/spiro-OMeTAD/Au PSCs was increased by 4.53% with the inclusion of the micropatterned NOA film. We achieved the water vapor transmission rate of 1.1 x 10(-3) g/m(2)/day at 65 degrees C and 85% relative humidity. To investigate the moisture barrier capability of the NOA/PET film, we encapsulated the (FAPbI(3))(0.85)(MAPbBr(3))(0.15)/spiroOMeTAD/Au PSCs with the films. We manufactured a water reservoir to direct contact with water on the NOA/ PET film and conducted water stability test on a 25 degrees C hot plate for over 540 h while monitoring the change in PCE. The PSCs showed little change in PCE after 540 h.