Tunable electrode-dependent switching characteristics of Se-Te-In chalcogenide thin films

Abstract

Chalcogenide glasses have garnered significant interest as potential materials for the creation of high-density, three-dimensional stackable cross-point array structures, particularly for memory devices. Chalcogenide glasses have emerged as promising candidates for high-density, three-dimensional stackable cross-point array structures. In this study, we delve into the intricate electrical switching behaviour of Se<inf>86−x</inf>Te<inf>14</inf>In<inf>x</inf> (x = 0, 2, 4, 6) chalcogenide glasses in the form of thin films, employing Aluminium (Al) as the top and bottom electrodes. Exhibiting the remarkable phase-changing characteristics of the material, the films showed memory-type switching behaviour. Remarkably, with an incremental change in Indium concentration from 0 to 6%, a linear reduction in the threshold voltage (V<inf>th</inf>) from 12.75 to 4.80 V was observed, underscoring the tunability of switching properties with respect to compositional variations. When the Al top electrode was substituted with Silver (Ag) the thin films’ electrical behaviour changed and this alteration instigated a shift in the switching mechanism. The films changed their characteristics from memory to threshold-switching behaviour, presenting a unique phenomenon in the realm of Se-Te-based chalcogenide glassy alloys. The presence of an active electrode (Ag) at the top facilitated the formation of temporary Ag filaments, making the device a programmable metallization cell (PMC) with remarkable threshold-switching capabilities with higher selectivity (∼ 5 × 103) and endurance of 104 cycles. The observed tunable attributes, contingent on the precise adjustment of Indium concentration and film thickness, underscore the immense potential of these films as highly efficient and adaptable unidirectional selectors and memory devices. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.