Extreme tunability in aluminum doped Zinc Oxide plasmonic materials for near-infrared applications

Abstract

Plasmonic materials (PMs), featuring large static or dynamic tunability, have significant impact on the optical properties due to their potential for applications in transformation optics, telecommunications, energy, and biomedical areas. Among PMs, the carrier concentration and mobility are two tunable parameters, which control the plasma frequency of a metal. Here, we report on large static and dynamic tunability in wavelengths up to 640 nm in Al-doped ZnO based transparent conducting degenerate semiconductors by controlling both thickness and applied voltages. This extreme tunability is ascribed to an increase in carrier concentration with increasing thickness as well as voltage-induced thermal effects that eventually diminish the carrier concentration and mobility due to complex chemical transformations in the multilayer growth process. These observations could pave the way for optical manipulation of this class of materials for potential transformative applications.

Assessment of a new ZnO:Al contact to CdZnTe for X- and gamma-ray detector applications

“…Details of the AZO deposition process were reported elsewhere. 20 In the present case, the ratio of the Zn:Al in the ALD cycle was maintained at 30:1, and the corresponding measured atomic concentration of Al was ∼ 3% (See Fig. 1 of Ref.…”

“…1 of Ref. 20). During this deposition, the temperature was maintained at 85-90 0 C. The thickness and the resistivity of the AZO film were 2500 Å and ∼4 x10 -2 ohm-cm, respectively.…”

Coupling of Surface Plasmon Polariton in Al-Doped ZnO with Fabry-Pérot Resonance for Total Light Absorption

“…The carrier concentration of AZO has been shown to be electrically tunable or thermally tunable via voltage biasing [39,40]. This change in carrier concentration is seen as a change in plasma frequency for AZO that effects the value of its permittivity Figure 4.…”

“…The optical properties of plasmonic and optical devices in semiconductors and transparent metal oxides can be tuned by altering their carrier concentration through voltages or heat [20,[32][33][34][35][36][37][38][39][40][41]. Very recently, indium tin oxide (ITO) and Ga-doped ZnO have been used to realize tunable TLA [33][34][35][36][37][38][39][40][41].…”

“…Very recently, indium tin oxide (ITO) and Ga-doped ZnO have been used to realize tunable TLA [33][34][35][36][37][38][39][40][41]. From the material side, ITO and Ga or Al-doped ZnO (AZO)-based transparent metal oxide exhibits tunable optical properties that can be thermally, electrically, or optically switched [33][34][35][36][37][38][39][40][41], and is compatible with standard complementary metal-oxide-semiconductor (CMOS) fabrication and integration procedures [40,42]. Furthermore, TLA can also be achieved near the epsilon-near-zero regime in ITO [33][34][35][36].…”