Herein, the electrical switching
behavior of both bulk and thin
film forms of Se86–x
Te14Bi
x
(0 ≤ x ≤
4) chalcogenide glasses was investigated. The melt–quench-derived
glasses were found to be amorphous, and the switching behavior exhibited
a threshold-type response below a certain current limit (I
th) for bismuth (Bi)-doped bulk samples. Interestingly,
as current levels surpassed this threshold, a noteworthy change occurred
in the switching behavior, converting it into a memory-type response.
The threshold voltage (V
th) exhibited
a decreasing trend from ∼228 V to ∼36 V with an increasing
Bi content, and differential scanning calorimetry (DSC) was utilized
to study the phase transition phenomena and thermal stability of the
amorphous glasses. These DSC results unequivocally confirmed that
the transition from amorphous to crystalline phase occurred readily
and at lower temperatures in the Se82Te14Bi4 composition. Furthermore, annealing studies were carried
out to gain insight into the phase transformations that occur when
the material makes the transition from an amorphous to a crystalline
state. Subsequently, the same melt–quench-derived glasses were
deposited as a thin film using physical vapor deposition (PVD) into
a three-layered Al/Se–Te–Bi/Al device, and the memory
switching voltage experienced a remarkable drop to 2.88 V compared
to the bulk material. This exploration sheds light on the captivating
electrical switching behavior of Se86–x
Te14Bi
x
chalcogenide
glasses and holds promise for potential applications spanning the
realm of emerging electronics and phase change material (PCM) devices.