Lee Cheng Chen Yiwang peace talks Nanchang University professor build self-portrait perovskite organic scaffold to control grain growth and stability

Organic-inorganic hybrid perovskite as the fastest growing and most promising candidate for next-generation thin-film photovoltaic material category, has sparked a great deal of global research boom in the photovoltaic field. Since 2009 perovskite used in solar cells as the light-absorbing material, the power conversion efficiency continue to make breakthroughs, from the initial 3.8% to 25.2%, comparable to monocrystalline silicon cells. However, an important factor in addition to excellent optical properties, the real limit perovskite solar cell (PVSCs) further comprises outdoor applications toxic lead ions, uncontrollability perovskite film formation device unsatisfactory stability, and the anti-solvent huge area difficult to realize a wearable battery under process limitations such as brittleness and perovskites. Professor Chen Yiwang and talk about Lee Cheng Nanchang University research team for the solar cell ion transport oxygen and water erosion perovskite cause stability problems, \”go-between\” comprehensive strategy to improve the perovskite solar cell stability and resistance to bending. Fluorinated carbon nanotubes and semiconductors made AIE molecules and calcium titanium solar filling defects in grain boundaries, and suppress ion migration of grain boundaries to realize the link, a substantial increase in stability of the device (Adv. Energy Mater. 2019, 9, 1900198, Adv. Funct. Mater. 2019, 29, 1808059, Chem. Commun. 2016, 52, 5674). It proposed a perovskite elastomeric repair defects in grain boundaries, to impart bending resistance of the active layer (Adv. Funct. Mater. 2017, 27, 1703061). Bionic mussels by crosslinking oxide nanocrystals overcomes the inherent brittleness of the inorganic interface layer, the interface layer is prepared high density inorganic atomic layer deposition process, to improve the stability of the perovskite solar cell (Adv. Mater. 2017, 29, 1606656 , Chem. Commun. 2019, 55, 3666, Chem. Commun. 2018, 54, 471). A novel self-tight polymer package perovskite interfacial layer prevents the water erosion of the perovskite oxide layer, the interface layer is introduced EVA glue, effectively improve the long term stability of the solar cell titanium, bending durability and water resistance, thereby producing rigid and flexible solar module 25 cm2 (Adv. Funct. Mater. 2019, 29, 1902629). Fluorine-containing enhancers doped PEDOT: PSS transparent electrode, meet high conductivity, high transparency and good mechanical flexibility, the perovskite for preparing a flexible solar cell module (Joule 2019, 3, 2205-2218) and forming a small amount of ink is stable PU and PbI 2, good control of the two-step blade process, a stable and efficient preparation of large-area solar cell module perovskite (J. Phys. Chem. C 2020, 10.1021 / acs.jpcc. 0c00908). Mature large Perovskite Thin Films always the key factor limiting PVSCs commercialized, although the scale can be derived for the preparation of a roll of roll printing or the like sequential deposition method has proven to be an effective strategy PVSCs high performance, but Professor Grätzel traditional two-step process is applicable only to create a mesoporous structure of the device, and a high temperature sintering process titanium dioxide and limit its use in a flexible device. On the other hand, in the plane PVSCs dense lead iodide (PbI 2) films severely inhibit permeation trimethylammonium iodide solution (the MAI), which led to incomplete conversion of the perovskite. Most of the perovskite can only stay in the early phase transition, from the surface of the substrate will be thrown by the centrifugal force, resulting in low utilization of the solution. Most of the current study only limited PbI2 reduce residual unreacted perovskite, such as optimizing deposition factor pathway regulates the formation and morphology of a thin film of perovskite lead iodide, but almost no attention perovskite solution utilization problem.

Recently, Professor Li Cheng Chen Yiwang talks Nanchang University team developed by one kind of lead iodide interspersed new independent longitudinal stent situ polymerization of methyl methacrylate (SMMA) constructing the stent may be a perovskite organic solution is limited within the network, and provide more efficient nucleation sites to promote crystal along a longitudinal stent growth. Moreover, the oligomer is further polymerized SMMA perovskite thin film during annealing and filled perovskite grain boundaries, to form defects can be passivated, mechanical stress is released, to suppress ion migration and cross-linked network of water / oxygen permeation. Finally, based on sMMAModified MAPbI3 exhibits excellent photoelectric conversion efficiency (20.12%) and excellent operational stability as a planar PVSCs light absorbing layer, and a hysteresis effect is negligible. More importantly, the respective flexible device can maintain initial efficiency of 72% after 5000 cycles withstand bending. The researchers believe that progress has opened up a new way for flexible electronics in the commercial development of a large area PVSCs. This related paper published in Advanced Materials (Adv Mater 2020, DOI:.. 10.1002 / adma.202000617) on entitled \”Crystal Growth via Controlling Autonomously Longitudinal Scaffold for Planar Perovskite Solar Cells\”. This article is the corresponding author Professor Lee Cheng Chen Yiwang peace talks Nanchang University. The first author is graduate student Xiaopeng master segment Nanchang University, co-first author of Nanchang University graduate Li Xiang.