硼掺杂对石墨烯量子点发光影响的理论研究

摘要

The absorption and emission spectra of graphene quantum dots (GQDs)and boron-doped GQDs were ex-plored by TDDFT method.The calculated results indicate that the doped boron atom can make a high redshift of ab-sorption and emission wavelength of GQDs.The doped boron atom located at the edge of GQDs makes higher red-shift.The doped-boron atom also greatly decreases the absorption and emission intensity of GQDs,which is inde-pendent of the position of boron atom.The molecular orbitals of GQDs and boron-doped GQDs were analyzed.The transition is charge transfer (CT)when boron locates at the edge of GQDs,which is different from the local excita-tion (LE)of GQDs with interior doped boron.%采用含时密度泛函（TDDFT）方法研究了石墨烯量子点（GQDs）和硼掺杂 GQDs 的吸收和发射光谱。计算结果表明，硼掺杂使 GQDs 的吸收和发射光波长红移，硼的位置越靠近 GQDs 边缘，波长红移越多。硼掺杂极大地降低了 GQDs 的吸收和发射光强度，这与掺杂时硼的位置无关。轨道分析表明，硼掺杂在边缘时，GQDs 中电子跃迁的类型为电荷转移跃迁，与硼掺杂在晶格内的局域激发不同。