Development of 'Eco-friendly' Next-generation Solar Cell Materials Without Toxic Lead Use

Dr. Choi Yong-chan's DGIST Team Develops Synthesis Method for Antimony Chalcoiodide

[Asia Economy Reporter Kim Bong-su] A fatal flaw of perovskite materials, which are attracting attention as next-generation solar cell materials, is that they use lead (Pb), which causes severe environmental pollution during production. A domestic research team has attracted attention by developing core technology for next-generation solar cell materials that do not use lead.

The Daegu Gyeongbuk Institute of Science and Technology (DGIST) announced on the 23rd that Dr. Yongchan Choi's Energy Convergence Research Department team developed core technology to control the composition of antimony chalcoiodide (Sb(S,Se)I), an eco-friendly next-generation photovoltaic material gaining attention for not using lead. It is expected to have a positive impact on the development of next-generation lead-free solar cells that do not contain lead in the future.

Recently, perovskite materials based on lead (Pb), which have high performance comparable to silicon and ease of fabrication, have been spotlighted as next-generation solar cell materials. However, the toxicity of lead (Pb) is a major obstacle to commercialization. Therefore, antimony chalcoiodide, a lead-free photovoltaic material, is attracting attention as a representative alternative, but related research remains in its early stages.

The research team succeeded in developing a material whose composition of antimony chalcoiodide can be controlled through a two-step solution process. In the first step, the team produced antimony chalcogenide (Sb2(S,Se)3), and in the second step, reacted it with antimony triiodide (SbI3) to convert it into antimony chalcoiodide.

Moreover, through this process, the team succeeded in fabricating antimony chalcoiodide Sb(S1-xSex)I material with well-controlled crystal structure, morphology, and electronic structure beyond simple composition control. Through electronic structure analysis, they pointed out the limitations of this material and introduced appropriate interfacial layers necessary for producing high-performance solar cells.

Dr. Choi said, "The method developed this time can be applied to the fabrication of various ternary chalcogen-halide materials, including antimony chalcoiodide," adding, "It is expected to serve as a foundation for the development of next-generation lead-free solar cells beyond simple photovoltaics in the future."

The research results were published online on the 16th in the international energy journal ‘ACS Applied Energy Materials’ and were selected as a supplementary cover paper.