Nanosecond Carrier Lifetimes in Solution-Processed Enargite (Cu3AsS4) Thin Films

Enargite (ENG) Cu3AsS4 is a promising material for photovoltaic applications due to its constituent earth abundant elements of differing ionic radii, ideal predicted optoelectronic properties, and demonstrated use in a working thin-film solar cell. However, little is known about ENG’s defect properties; such knowledge is necessary to assess its potential for future use in high-efficiency devices. One indicator of a material’s quality is its photogenerated carrier lifetime, which can be related to its bulk defect properties. Here, we use a combination of time-resolved terahertz spectroscopy (TRTS) and time-resolved photoluminescence (TRPL) to assess carrier dynamics in ENG thin films processed from nanoparticle precursors. The Shockley-Read-Hall (SRH) lifetimes are on the multi-nanosecond scale, a promising value for an emerging material. These results suggest that ENG is worthy of further research and development efforts with an eye towards future photovoltaic applications.

辉砷铜矿（Enargite，ENG）Cu₃AsS₄是一种极具潜力的光伏应用材料，其组成元素在地壳中储量丰富且离子半径各异，同时具备理想的预测光电性能，且已被证实可应用于实际薄膜太阳能电池中。然而目前学界对ENG的缺陷特性仍知之甚少，而此类认知是评估其未来在高效器件中应用潜力的必要前提。材料品质的核心表征指标之一为光生载流子寿命，该参数与材料的体相缺陷特性直接相关。本研究结合时间分辨太赫兹光谱（time-resolved terahertz spectroscopy，TRTS）与时间分辨光致发光（time-resolved photoluminescence，TRPL）两种技术，对由纳米颗粒前驱体制备的ENG薄膜的载流子动力学行为开展了表征分析。肖克利-里德-霍尔（Shockley-Read-Hall，SRH）寿命处于纳秒级区间，这一数值对于这类新兴材料而言极具应用前景。上述研究结果表明，ENG值得进一步开展研发工作，以推进其在未来光伏领域的实际应用。