Additive engineering for Sb₂S₃ indoor photovoltaics with efficiency exceeding 17

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Indoor photovoltaics (IPVs) are crucial for powering Internet of Things (IoT) electronics sustainably.
• Antimony sulfide (Sb2S3) is a promising IPV material, but its performance is limited by nonradiative recombination in absorber films.
• Additive engineering offers a strategy to improve the properties of solution-processed films.

Purpose of the Study:

• To investigate the effect of monoethanolamine (MEA) as an additive in Sb2S3 precursor solutions.
• To enhance the quality of Sb2S3 absorber films for improved indoor photovoltaic performance.
• To achieve high power conversion efficiency (PCE) in Sb2S3-based IPVs for IoT applications.

Main Methods:

• Controlled deposition of Sb2S3 films using MEA in the precursor solution.
• Characterization of Sb2S3 film properties, including grain boundary density, band positions, and carrier concentration.
• Fabrication and testing of Sb2S3 solar cells and IPV minimodules under various illumination conditions.
• Computational modeling to understand the role of MEA in film nucleation and growth.

Main Results:

• MEA addition enabled the deposition of high-quality Sb2S3 films with reduced grain boundaries and optimized band positions.
• MEA incorporation enhanced heterogeneous nucleation, leading to larger grain sizes and faster deposition rates.
• Sb2S3 solar cells achieved a PCE of 7.22% under AM1.5G and a record 17.55% PCE for IPVs under 1000 lux WLED illumination.
• High-performance Sb2S3 IPV minimodules successfully powered IoT wireless sensors for continuous environmental monitoring.

Conclusions:

• MEA is an effective additive for improving Sb2S3 film quality and photovoltaic performance.
• The developed Sb2S3 IPVs demonstrate significant potential for powering IoT devices and enabling long-term energy harvesting.
• This work highlights Sb2S3 photovoltaics as a viable technology for indoor energy harvesting applications.