Antimony thin films demonstrate programmable optical nonlinearity

Abstract

The use of metals of nanometer dimensions to enhance and manipulate light-matter interactions for emerging plasmonics-enabled nanophotonic and optoelectronic applications is an interesting yet not highly explored area of research beyond plasmonics. Even more importantly, the concept of an active metal that can undergo an optical nonvolatile transition has not been explored. Here, we demonstrate that antimony (Sb), a pure metal, is optically distinguishable between two programmable states as nanoscale thin films. We show that these states, corresponding to the crystalline and amorphous phases of the metal, are stable at room temperature. Crucially from an application standpoint, we demonstrate both its optoelectronic modulation capabilities and switching speed using single subpicosecond pulses. The simplicity of depositing a single metal portends its potential for use in any optoelectronic application where metallic conductors with an actively tunable state are important.

Mechanism of amorphous phase stabilization in ultrathin films of monoatomic phase change material

“…12 Switchable antimony films with thickness below 15 nm have also been proposed very recently for photonic applications. 13 Molecular dynamics (MD) simulations based on Density Functional Theory (DFT) revealed that the protocol used to generate the amorphous phase has strong effects on the crystallization kinetics of Sb. 10 An abrupt quenching from the melt to 300 K yielded indeed an amorphous model that did not crystallize by homogeneous nucleation over 0.8 ns, while a supercritical nucleus appeared within 100 ps at 300 K in a model quenched from 900 to 300 K in about 60 ps.…”

Change in Structure of Amorphous Sb–Te Phase‐Change Materials as a Function of Stoichiometry

“…The reduction in average charge for the Sb atoms and the decrease in Te concentration in Sb-rich alloys are expected to reduce the long-term mass transport. In the extreme case of pure Sb, [102][103][104][105] the absence of charge transfer should lead to much improved cycling performance.…”

Tailoring the Structural and Optical Properties of Germanium Telluride Phase-Change Materials by Indium Incorporation

“…For verification, we carried out optical response calculations using the relaxed crystalline and amorphous IGT structures. We focused on the spectrum range from 400 to 1600 nm, covering both the visible light region (∼400 nm to 800 nm) for optical displays [19][20][21] and the telecom wavelength bands (∼1500 to 1600 nm) for silicon-waveguideintegrated photonic applications [23][24][25][26]. As shown in Figure 5a, the optical absorption and reflectivity profiles vary slightly with the chemical compositions in the amorphous phase, while strong changes are found in the crystalline phase.…”

“…As announced by STMicroelectronics, PCRAM will be used as embedded memory, replacing Flash memory, for their future microcontroller units (MCU) for the automotive industry [7]. Moreover, PCRAM is also being exploited for more advanced applications, including neuro-inspired computing [9][10][11][12][13][14][15], stochasticity-based computing [16,17], flexible electronics [18], optical displays [19][20][21], all-optical computers [22][23][24][25][26], low-loss optical modulators [27], metasurfaces [28][29][30][31][32] and others [33,34].…”