Scalable Production of High Performance Flexible Perovskite Solar Cells via Film-Growth-Megasonic-Spray-Coating System

Substrate Modifications for Stability Improvements of Flexible Perovskite Solar Cells

“…Flexible perovskite solar cells (fPSCs) [ 1–48 ] are of significant interest due to their high power‐per‐weight ratios, potential for low cost fabrication on inexpensive flexible substrates, such as roll‐to‐roll (R2R) manufacturing, and the rising demand for niche applications of solar power (vehicle integrated photovoltaics, space applications, Internet of Things (IoT), wearable electronics, etc.). [ 1–3,5,6,9 ] A significant obstacle toward commercialization fPSCs, among others, is their lower efficiency and stability compared to rigid devices.…”

“…Stability considerations of fPSCs typically take into account mechanical stability and environmental stability. [ 2 ] Consequently, mechanical stability investigations of fPSCs [ 2,14,15,17–22,24–28,32–34,36,37,44–48 ] and environmental stability in ambient without illumination have been very common. [ 2,14–21,24,26,28,32,33,36–39,44,46–48 ] Impressive improvements have been achieved in mechanical stability, with reports of devices being able to withstand 10 000 bending cycles at a radius 0.5 mm.…”

“…For example, a T 90 of 150 h in high efficiency flexible tandem devices has been directly attributed to high moisture and oxygen permeability of flexible polymer substrate. [43] While advanced encapsulation, such as the use of glass or barrier foils, could improve operational stability in ambient, [30,34] it is desirable to investigate whether simple modifications of flexible substrates could have a significant effect on device stability as the glass encapsulation is not desirable and ultrahigh barrier foils have relatively high cost. [40] The effect of ultrahigh barrier foils on the shelf-life of perovskite devices has been investigated, but there was no comprehensive investigation of the effect of type of barrier on the stability under illumination.…”