Room-temperature processed high-quality SnO₂ films by oxygen plasma activated e-beam evaporation

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Tin oxide (SnO₂) is a key electron transport layer material for perovskite solar cells (PSCs).
• Low-temperature processing of SnO₂ films is essential for fabricating efficient PSCs and flexible electronic devices.
• Conventional e-beam evaporation methods struggle to produce stoichiometric SnO₂ films at low temperatures.

Purpose of the Study:

• To develop a low-temperature fabrication method for stoichiometric SnO₂ films.
• To investigate the properties of SnO₂ films produced via oxygen plasma-activated e-beam evaporation.
• To promote the use of SnO₂ in perovskite solar cells and flexible devices.

Main Methods:

• Fabrication of SnO₂ films using an oxygen plasma-activated e-beam evaporation technique at room temperature.
• Utilizing the strong oxidation activity of oxygen plasma to control SnO_x stoichiometry.
• Characterization of film properties including uniformity, transmittance, hall mobility, and hydrophilicity.

Main Results:

• Achieved uniform SnO₂ films with a surface roughness (R_q) of 3.05 nm.
• Obtained high optical transmittance (T > 90%) and high electron hall mobility (μ_e = 10.8 cm² V^-1 s^-1).
• Demonstrated good hydrophilic properties with a water contact angle of 19°.

Conclusions:

• Oxygen plasma-activated e-beam evaporation is a viable method for low-temperature fabrication of high-quality SnO₂ films.
• The developed SnO₂ films possess excellent properties suitable for electron transport layers in PSCs.
• This technique facilitates the advancement of SnO₂-based perovskite solar cells and flexible electronics.