A Bionic Interface to Suppress the Coffee‐Ring Effect for Reliable and Flexible Perovskite Modules with a Near‐90% Yield Rate

Abstract

The certified champion power conversion efficiency (PCE) of perovskite solar cells (PSCs) has been impressively reported as high as 25.8%. [4] It is worth noting that the high-efficiency device is usually based on a thick, heavy, and fragile rigid substrate, which severely restricts roll-to-roll (R2R) manufacturing and diversified application scenarios. [5][6][7] Compared with the rigid ones, flexible PSCs have natural superiorities of lightweight and portable compatibility, [8][9][10][11] which boost a huge potential market in wearable application, [12] intelligent vehicles, [13] photovoltaic building integration, [14] and space field. [15] Meanwhile, low-temperature processable perovskite film is more compatible with the flexible substrates than the former traditional photovoltaics. [16][17][18] Up to now, the champion PCE of flexible PSCs so far has been beyond 21% based on a 0.04 cm 2 laboratorial size. [19] However, the scalability is an important prerequisite for manufacturing and commercialization of flexible PSCs. [20,21] To promote the large-scale manufacturing of flexible PSCs, meniscus printing, which has close analogy to R2R technology, [22] is widely used because of cost-effective, highthroughput, and excellent low-temperature morphologicalThe inhomogeneity, poor interfacial contact, and pinholes caused by the coffee-ring effect severely affect the printing reliability of flexible perovskite solar cells (PSCs). Herein, inspired by the bio-glue of barnacles, a bionic interface layer (Bio-IL) of NiO x /levodopa is introduced to suppress the coffee-ring effect during printing perovskite modules. The coordination effect of the sticky functional groups in Bio-IL can pin the three-phase contact line and restrain the transport of perovskite colloidal particles during the printing and evaporation process. Moreover, the sedimentation rate of perovskite precursor is accelerated due to the electrostatic attraction and rapid volatilization from an extraordinary wettability. The superhydrophilic Bio-IL affords an even spread over a large-area substrate, which boosts a complete and uniform liquid film for heterogeneous nucleation as well as crystallization. Perovskite films on different large-area substrates with negligible coffee-ring effect are printed. Consequently, inverted flexible PSCs and perovskite solar modules achieve a high efficiency of 21.08% and 16.87%, respectively. This strategy ensures a highly reliable reproducibility of printing PSCs with a near 90% yield rate.

Spring‐Like Ammonium Salt Assisting Stress Release for Low‐Temperature Deposited FAPbI3 Films Toward Flexible Photovoltaic Application

“…received extensive attention and research to supplement some application scenarios where rigid devices cannot be applied. [3][4][5][6][7] The substrates of mainstream FPSCs are thermoplastic polymer materials polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). [8,10] Due to the inherent characteristics of thermoplastic polymers, they will soften and bend during high temperature annealing process, resulting in poor thermal uniformity of the perovskite films.…”

Grain‐Slip Derived Network Topology to Remarkable Strength–Toughness Combination of Perovskite Film for Flexible Solar Cells

“…[16][17][18][19][20][21][22][23][24][25][26][27] Flexible devices based on them not only have high power conversion efficiency (PCE) but also are lightweight. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] However, only around 1.1% elongation at break and fracture strength generally below 50 MPa limit the application of perovskite films in wearable devices. [43][44][45] Although some works attempted to increase the toughness of perovskite films, [46][47][48] the simultaneous improvement of strength and toughness is a huge challenge.…”

Recent Progress in Large-Area Perovskite Photovoltaic Modules

“…In addition to controlling solvent evaporation, regulating the microscale ink flow dynamics is also an effective way to control the nucleation and grain growth during the wet film drying process [112]. Huang and coauthors [59] reported a method for controlling the fluid drying dynamics by introducing a surfactant of L-α-phosphatidylcholine (LP).…”