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Photoluminescence Enhancement in Formamidinium Lead Iodide Thin Films
Author(s) -
Fang HongHua,
Wang Feng,
Adjokatse Sampson,
Zhao Ni,
Loi Maria Antonietta
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201600715
Subject(s) - photoluminescence , formamidinium , materials science , thin film , perovskite (structure) , iodide , optoelectronics , analytical chemistry (journal) , nanotechnology , chemical engineering , inorganic chemistry , chemistry , organic chemistry , engineering
Formamidinium lead iodide (FAPbI 3 ) has a broader absorption spectrum and better thermal stability than the most famous methylammonium lead iodide, thus exhibiting great potential for photovoltaic applications. In this report, the light‐induced photoluminescence (PL) evolution in FAPbI 3 thin films is investigated. The PL intensity evolution is found to be strongly dependent on the atmosphere surrounding the samples. When the film is exposed to air, its photoluminescence intensity is enhanced more than 140 times after continuous ultraviolet laser illumination for 2 h, and the average lifetime is prolonged from 17 to 389 ns. The enhanced photoluminescence implies that the trap density is significantly reduced. The comparative study of the photoluminescence properties in air, nitrogen, and oxygen/helium environment suggests that moisture is important for the PL enhancement. This is explained in terms of moisture‐assisted light‐healing effect in FAPbI 3 thin films. With this study, a new method is demonstrated to increase and control the quality of hybrid perovskite thin films.