Core Viewpoint - The research team at the Qingdao Institute of Bioenergy and Process Research has developed a new mechanism to control metal ion migration in copper zinc tin sulfur selenium (CZTSSe) photovoltaic materials, achieving a power conversion efficiency of over 15%, positioning China at the forefront of next-generation solar cell research [1][2]. Group 1: Research Breakthrough - The new mechanism involves introducing a Li2SnS3 interface phase that guides metal ions during the phase transition process, leading to more uniform and stable crystal structures [1]. - The power conversion efficiency of the CZTSSe solar cells reached 15.45%, with an internationally certified efficiency of 15.04% [2]. - The open-circuit voltage surpassed 600 millivolts for the first time under narrow bandgap conditions, addressing performance bottlenecks in this type of photovoltaic device [2]. Group 2: Material Advantages - CZTSSe materials are characterized by abundant elemental reserves, low cost, high stability, and non-toxicity, making them a focus in the photovoltaic field [1]. - The new approach significantly reduces internal defects in the CZTSSe materials, fundamentally enhancing the power generation capability of the solar cells [2].