Implementation of Thermal-Triggered Binary–Ternary
Switchable Memory Performance in Zn/polysulfide/organic Complex-Based
Memorizers by Finely Modulating the S62– Relaxation
posted on 2023-12-22, 20:06authored byXiaoli Lin, Panke Zhou, Yiqun Gao, Tao Li, Xiong Chen, Haohong Li, Rong Jiang, Zhirong Chen, Huidong Zheng
Polysulfide-based
multilevel memorizers are promising as novel
memorizers, in which the occurrence of Sn2– relaxation is key for their multilevel memory.
However, the effects of crystal packing and the side group of organic
ligands on Sn2– relaxation
are still ambiguous. In this work, ionic [Zn(S6)2·Zn2(Bipy)2SO4 (1), Zn(S6)2·Zn(Pmbipy)3 (2)] and neutral [ZnS6(Ombipy) (3),
ZnS6(Phen)2 (4)] Zn/polysulfide/organic
complexes with different packing modes and structures of organic ligands
have been synthesized and were fabricated as memory devices. In both
ionic and neutral Zn complexes, the S62– relaxation will be blocked by steric hindrances due to the packing
of counter-cations and hydrogen-bond restrictions. Consequently, only
the binary memory performances can be seen in FTO/1/Ag,
FTO/2/Ag, and FTO/4/Ag, which originate
from the more condensed packing of conjugated ligands upon electrical
stimulus. Interestingly, FTO/3/Ag illustrates the unique
thermally triggered reversible binary–ternary switchable memory
performance. In detail, after introducing a methyl group on the 6′-position
of bipyridine in ZnS6(Ombipy) (3), the ring-to-chain
relaxation of S62– anions at room temperature
will be inhibited, but it can happen at a higher temperature of 120
°C, which has been verified by elongated S–S lengths and
the strengthened C–H···S hydrogen bond upon
heating. The rules drawn in this work will provide a useful guide
for the design of stimulus-responsive memorizers that can be applied
in special industries such as automobile, oil, and gas industries.