Vertically Aligned One-Dimensional Crystal-Structured Sb₂Se₃ for High-Efficiency Flexible Solar Cells via Regulating...

Area of Science:

• Materials Science
• Solid-State Physics
• Nanotechnology

Background:

• Antimony selenide (Sb₂Se₃) shows promise for flexible electronics due to its 1D structure and optoelectronic properties.
• Controlling crystalline orientation, particularly the vertical (001) orientation, is crucial for optimizing Sb₂Se₃ device performance.
• Current methods struggle with precise orientation control, limiting device efficiency.

Purpose of the Study:

• To achieve unprecedented control over the (001) orientation of Sb₂Se₃ films on flexible substrates.
• To investigate the impact of controlled orientation on the performance of flexible Sb₂Se₃ solar cells.
• To elucidate the mechanisms behind improved device performance resulting from the (001) orientation.

Main Methods:

• Regulating selenization kinetics to balance Se vapor particle collision rate and kinetic energy on an Sb film surface.
• Utilizing a flexible Mo-coated mica substrate for Sb₂Se₃ film growth.
• Characterizing the film's crystalline orientation and device performance.

Main Results:

• Achieved unprecedented control of (001) orientation in Sb₂Se₃ films on flexible Mo-coated mica.
• Fabricated flexible Sb₂Se₃ solar cells with a record 8.42% efficiency and 0.47 V open-circuit voltage (V_OC).
• Observed formation of a MoSe₂ interlayer and Se-rich state, enhancing the absorber layer and back contact.

Conclusions:

• Controlled (001) orientation of Sb₂Se₃ films significantly boosts flexible solar cell performance.
• The vertical van der Waals gaps in the (001) orientation facilitate Se diffusion and interlayer formation.
• This strategy offers a pathway for developing high-performance flexible photoelectric devices using 1D materials.