posted on 2020-03-23, 13:39authored byChen Sun, Ya-Hui Guo, Yun Yuan, Wen-Xin Chu, Wen-Li He, Hang-Xin Che, Zhi-Hong Jing, Cheng-Yang Yue, Xiao-Wu Lei
In the past few decades, organic–inorganic
hybrid metal halides acting as single-component white light emission
diodes (LEDs) have attracted extensive attentions, but most of the
studies concentrate on the low-dimensional lead perovskites. Here,
by using the nontoxic silver as optically active metal center, a series
of hybrid silver halides based on one-dimensional structures were
constructed and realized broadband white light emission. Compounds
[H2DABCO][Ag2X4(DABCO)] (X = Br (1), I (2)) feature one-dimensional [Ag2X4(DABCO)]2– structures charged balanced
by [H2DABCO]2+ cations. Compound 1 exhibits an efficient broadband white-light emission with photoluminescence
quantum efficiency (PLQE) of about 2.1% and excellent photochemical
stability, while compound 2 gives a broadband yellow-white
emission centered at 556 nm. [HDABCO]3Ag5Cl8 (3) gives a strong broadband yellow emission
(585 nm) with high PLQE of 6.7%, which can be easily fabricated as
a white light emitting device. Based on the temperature-dependent,
particle-size-dependent, and time-resolved PL measurements as well
as other detailed studies, the broadband white-light emissions are
ascribed to the synergetic effects of the organic and inorganic components.
Our work provides a unique structural assembly method to explore lead-free
single-component white-light illuminants from molecular level.