All-Inorganic CsPbI3 Perovskite Phase-Stabilized by Poly(ethylene oxide) for Red-Light-Emitting Diodes

作者：Jeong Beomjin; Han Hyowon; Choi Yung Ji; Cho Sung Hwan; Kim Eui Hyuk; Lee Seung Won; Kim Jong Sung; Park Chanho; Kim Dongho; Park Cheolmin

来源：Advanced Functional Materials, 2018, 28(16): 1706401.

DOI：10.1002/adfm.201706401

<jats:title>Abstract</jats:title><jats:p>Despite the excellent photoelectronic properties of the all‐inorganic cesium lead iodide (CsPbI<jats:sub>3</jats:sub>) perovskite, which does not contain volatile and hygroscopic organic components, only a few CsPbI<jats:sub>3</jats:sub> devices are developed mainly owing to the frequent formation of an undesirable yellow δ‐phase at room temperature. Herein, it is demonstrated that a small quantity of poly(ethylene oxide) (PEO) added to the precursor solution effectively inhibits the formation of the yellow δ‐phase during film preparation, and promotes the development of a black α‐phase at a low crystallization temperature. A systematic study reveals that a thin, dense, pinhole‐free CsPbI<jats:sub>3</jats:sub> film is produced in the α‐phase and is stabilized with PEO that effectively reduces the grain size during crystallization. A thin α‐phase CsPbI<jats:sub>3</jats:sub> film with excellent photoluminescence is successfully employed in a light‐emitting diode with an inverted configuration of glass substrate/indium tin oxide/zinc oxide/poly(ethyleneimine)/α‐CsPbI<jats:sub>3</jats:sub>/poly(4‐butylphenyl‐diphenyl‐amine)/WO<jats:sub>3</jats:sub>/Al, yielding the characteristic red emission of the perovskite film at 695 nm with brightness, external quantum efficiency, and emission band width of ≈101 cd m<jats:sup>−2</jats:sup>, 1.12%, and 32 nm, respectively.</jats:p>

• 出版日期2018-4-18