Doped SnO₂ transparent conductive multilayer thin films explored by continuous composition spread

Area of Science:

• Materials Science
• Solid State Physics
• Thin Film Technology

Background:

• Pure tin dioxide (SnO₂) thin films are widely used as transparent conducting oxides.
• Doping SnO₂ can modify its electrical and optical properties, but optimizing dopant concentration is crucial.
• Oxygen vacancies are known to influence the conductivity of metal oxide semiconductors.

Purpose of the Study:

• To investigate the effect of manganese (Mn) doping on the electrical resistivity of SnO₂ thin films.
• To determine the optimal Mn concentration for minimizing resistivity in SnO₂ thin films.
• To fabricate and characterize multilayer transparent conducting oxide films using optimized Mn-doped SnO₂.

Main Methods:

• Fabrication of Mn-doped SnO₂ thin films using the continuous composition spread (CCS) method at room temperature.
• Characterization of film properties, including electrical resistivity and Fourier Transform Infrared Spectroscopy (FT-IR) for vibrational analysis.
• Deposition of Mn-doped SnO₂/Ag/Mn-doped SnO₂ multilayer structures via on-axis radio frequency (RF) sputtering.

Main Results:

• Mn doping generated oxygen vacancies in SnO₂ films, leading to lower resistivity compared to pure SnO₂.
• Resistivity decreased with increasing Mn content up to an optimal concentration of 2.59 wt %, achieving a minimum of 0.29 Ω-cm.
• The optimized Mn-doped SnO₂/Ag/Mn-doped SnO₂ multilayer films exhibited a resistivity of 7.35 × 10⁻⁵ Ω-cm and >86% transmittance at 550 nm.

Conclusions:

• Mn doping is an effective strategy for reducing the electrical resistivity of SnO₂ thin films by introducing oxygen vacancies.
• The study identified an optimal Mn doping concentration for SnO₂ thin films, significantly enhancing their potential for transparent conducting applications.
• Multilayer structures incorporating optimized Mn-doped SnO₂ demonstrate promising performance as transparent conducting oxides.