课题组硕士生曾程在自然指数(Nature index)期刊Applied Physics Letters上发表论文

近日，课题组成员曾程同学在刘老师的指导下，以第一作者在自然指数(Nature index)期刊Applied Physics Letters上发表题为“Observation of split defect-bound excitons in twisted WSe2/WSe2 homostructures(WSe2/WSe2扭角同质结中局域激子劈裂特性的研究)”的实验论文。  

     二维过渡金属二卤化金属(TMDC)及其异质结构中的激子效应得到了广泛的研究。值得注意的是，由扭曲的异质结构中的莫尔超晶格引起的莫尔激子引起了极大的关注，证明了人工激子晶体的实用性。此外，最近的研究表明，同质结构中的激子态还表现出新颖的性质，值得进一步发展。在这里，我们介绍了一种用于制造规则或扭曲同质构结构的设计堆叠技术。利用这种策略将单层WSe₂重新组装成扭曲的同质结构，并且通过在光致发光(PL)光谱中确定了来自该结构的各种激子。有趣的是，我们在缺陷结合的激子中发现了异常的等距劈裂现象。实验结果表明这种现象归因于各种缺陷状态和局部堆叠图案。这种解释得到理论计算的支持，理论计算显示了能带结构对不同缺陷状态和局部堆叠模式的依赖性。这些非常规的缺陷结合激子是同质结构研究的关键组成部分，突显了人工操纵局部激子在实际应用中的可行性。

文章得到了审稿人的高度评价：

“The authors thoughtfully addressed my questions and provided additional experimental data. In particular, I am more confident that their observation of split defect peaks is related to the moire superlattice, and I appreciate the additional data comparing the monolayer to homostructure PL. This paper provides an interesting perspective on defect states in a moire superlattice, which to my knowledge haven't been considered previously. I am happy to support this manuscript for publication in APL”. 

论文链接：https://aip.scitation.org/doi/10.1063/5.0015431

Comments:

• This observation is significant because it provides new insights into the behavior of excitons in two-dimensional materials. The split defect-bound excitons in twisted WSe₂/WSe₂ homostructures demonstrate that these materials have unique properties that are different from traditional materials. This could have important implications for the development of new optoelectronic devices and could lead to the discovery of new materials with unique optical and electrical properties. Overall, this observation highlights the potential for twisted two-dimensional materials to be used in a variety of applications and provides a foundation for future research in this field.