Planar Perovskite Solar Cells using CH₃NH₃PbI₃ Films: A Simple Process Suitable for Large‐Scale Production

Abstract

Despite the rapid progress of the power conversion efficiency (PCE) of perovskite solar cells, the reproducibility, stability, and large‐scale production are major challenges. Here, we present a simple and quick solution‐depositing process to achieve high‐quality perovskite films by adding an insulating polymer of polyacrylonitrile (PAN) as a film‐forming additive into the CH3NH3PbI3 solution. With the CH3NH3PbI3:PAN films serving as an active layer, planar heterojunction perovskite solar cells show a PCE of 13.08 % at an area of 0.12 cm2 and 7.32 % at a large area of 1.0 cm2. The PCE loss is only about 40 % from the small‐area to larger‐area devices fabricated by using a solution‐based deposition process. The measurements were performed in air without any device encapsulation. We also used the conjugated polymer poly(3‐hexylthiophene) (P3HT) as the alternative for PAN. The device performance indicates that the conjugated polymer is unsuitable as the additive, which we attribute to the photo‐induced charge transfer between CH3NH3PbI3 and P3HT.

Recent Advances in Flexible Perovskite Solar Cells: Fabrication and Applications

“…Fort he solution-processed methods,a dditives offer an efficient way to improve the quality of the perovskite films. [75] Researchers have developed and used many different additives in the precursor solution for the low-temperature perovskite fabrication procedure,s uch as polymers, [76] fullerene, [77] inorganic acid, [78] solvents, [51,[79][80][81] and so on. [82][83][84] To resolve the issue of poor coverage caused by the pristine MAPbI 3Àx Cl x ,S u sg roup first added poly(ethylene glycol) (PEG) to the perovskite precursor solution to fabricate highperformance PSCs via al ow-temperature process,a nd they found that the use of 1wt%of PEG can cause a25%increase in the PCE.…”

Solution-processed all-inorganic bismuth-triiodide thin-films for photovoltaic application

“…58 Furthermore, the material is solution-processable allowing for low-cost fabrication, as has been shown to work with a variety of different hole and electron contact materials. [59][60][61] Lastly, the material is defect-tolerant, such that electronic and structural defects do not affect the transport properties. 62,63 However, as discussed previously, the material suffers from poor stability, which remains a significant challenge moving forward.…”

Progress in Multifunctional Molecules for Perovskite Solar Cells

“…Due to the coordination of the –CN and –C=O groups with PbI 2 , E2CA is located at the GBs by chemical anchors, thus passivating the defects at GBs and leading to high device efficiency of 21.03%, blocking GBs channel for moisture penetration, and enhancing themoisture‐resisting properties of perovskite. Other polymers including poly(ethylene glycol), poly[9,9‐bis (3'‐(N,N'‐dimethylamino‐propyl)‐2,7‐fluorene)‐alt‐2,7‐(9,9‐dioctylfluorene)], polyvinylpyrrolidone, polyacrylonitrile, and so on are also used as additives to the PSCs to improve its properties …”