Wafer-Scale Room-Temperature Processing of Lead-Free Perovskites for Optoelectronic Applications

Area of Science:

• Materials Science
• Optoelectronics
• Chemical Engineering

Background:

• Metal halide perovskites are crucial for optoelectronics but often contain toxic lead or lack stability.
• Lead-free alternatives like tin perovskites are unstable, and antimony perovskites require inefficient synthesis methods.
• Existing methods for antimony perovskites are low-throughput, use hazardous solvents, and offer limited control over film properties.

Purpose of the Study:

• To develop a scalable, environmentally friendly synthesis method for lead-free antimony perovskites.
• To demonstrate wafer-scale, room-temperature fabrication of high-quality Cs3Sb2Br9 and Cs3Sb2I9 thin films.
• To evaluate the optoelectronic performance of these novel perovskite films for device applications.

Main Methods:

• Radio frequency magnetron sputtering was employed for thin-film deposition at room temperature.
• The process is scalable, solvent-free, and utilizes established semiconductor manufacturing techniques.
• Material characterization included crystallinity, optical bandgap tuning, and device integration into photodetectors.

Main Results:

• Achieved wafer-scale, single-phase crystalline Cs3Sb2Br9 and Cs3Sb2I9 thin films.
• Demonstrated tuneable optical bandgaps from 2.17 to 2.71 eV, suitable for UV-visible optoelectronics.
• Fabricated photodetectors with high photoresponsivity (3.3 A/W), bandwidth (11 kHz), dynamic range (165 dB), and detectivity (1.7 × 10^15 Jones).

Conclusions:

• Magnetron sputtering is a viable platform for scalable, lead-free perovskite optoelectronics.
• Antimony perovskites synthesized via sputtering offer enhanced stability and performance.
• This work paves the way for environmentally friendly, high-performance optoelectronic devices beyond photovoltaics.