Defect passivation strategy sets new performance benchmark for Sb₂S₃ solar cells

A research team led by Profs. Wang Mingtai and Chen Chong from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed an antimony trisulfide (Sb₂S₃) solar cell with a record conversion efficiency of 8.21%. This achievement marks the highest performance ever reported for this type of solar cell.

The study was published in Advanced Energy Materials.

Sb₂S₃ has drawn increasing attention as a promising light-absorbing material due to its abundance, non-toxicity, and favorable optoelectronic properties. However, devices fabricated via solution methods typically suffer from high defect densities and interface mismatches, which limit carrier transport and restrict photovoltaic conversion efficiencies to around 6–7%.

To overcome these challenges, the researchers proposed a full-dimensional defect passivation approach using the permeation effect of degradable phenethylammonium iodide (PEAI) in amorphous Sb₂S₃ films.

PEAI pretreatment of amorphous Sb₂S₃ films enables [hk1]-oriented crystallization, full-dimensional defect passivation (bulk and interfaces), and dual-interface energy-level reconstruction via Cd-I and Sb-I bonding. The PEAI reduces CdS surface energy and preferentially adsorbs on Sb₂S₃ (211) planes, promoting [hk1] orientation and enhancing carrier transport.

Furthermore, the penetrated PEAI increases the carrier lifetime by a factor of 3.7, verifying effective defect suppression.

As a result, the researchers successfully fabricated an Sb₂S₃ bulk heterojunction solar cell with a conversion efficiency of 8.21%, the highest reported to date.

This work sets a new performance benchmark for Sb₂S₃ solar cells and provides valuable insights for the design of next-generation, high-efficiency thin-film solar cells.