Zhao Hongjia, an undergraduate student at DBJI, has published a research paper as the first author in Nanoscale, a high-impact SCI journal in the field of nanoscience and technology. The paper is titled"Structural Defects Dependence of the Second-Harmonic Generation in Monolayer MoS2". Using density functional theory calculations combined with a homegrown SHG calculation program developed by the research group of Prof. Gao Junfeng, Zhao systematically investigated the influence of typical defect types and densities on the SHG properties of monolayer MoS₂. The study demonstrates that by tuning the type and density of defects, the SHG performance of monolayer MoS₂ can be effectively designed and optimized for various applications, including broadband frequency conversion, long-wave infrared nonlinear optical devices, and communication-band devices.

Fig. 1 Schematic atomic structures of perfect MoS₂ and five different defective configurations

Fig. 2 Band structures of perfect and defective MoS₂

Fig. 3 Schematic diagram of the strongest SHG response component in perfect and defective MoS₂

Zhao consistently ranks top of his grade academically and takes an active part in various research and practical activities. Under the supervision of Prof. Gao Junfeng, Zhao has conducted various technical explorations, received multiple national awards, and obtained funding for undergraduate research. His achievements highlight the effectiveness of the DBJI's innovative talent cultivation for outstanding undergraduates.

Zhao Hongjia conducts research work at his workstation