论文标题
区域折叠的长度声音声子驱动胶体CDSE纳米板超级矩阵驱动自被捕的状态发射
Zone-folded longnitude acoustic phonons driving self-trapped state emission in colloidal CdSe nanoplate superlattice
论文作者
论文摘要
胶体镉粉核苷纳米板是二维半导体，在发光技术中显示出很大的应用前景。自被捕状态（STS）是一种特殊的局部状态，起源于强电子偶联（EPC），由于其宽带发射线宽，在一步白光亮度方面具有巨大的潜力。但是，由于其内在的EPC性质，因此在辣椒剂纳米晶体中实现STS极具挑战性。通过通过胶体CDSE纳米板（NPLS）的自组装构建混合晶格（SL）结构，我们证明了区域折叠的长度声音声子（ZFLAP）的出现与单分散的NPL不同，并观察到450-600 nm的光谱范围内的宽带STS发射。通过飞秒瞬时吸收和冲动振动光谱，我们揭示了STS的时间尺度为〜500 fs，并由具有Huang-Rhys参数的强烈耦合和Zflap的强耦合驱动。我们的发现为通过人工设计和建造混合周期性结构提供了优于单一材料优化的混合周期结构，为产生和操纵STS排放提供了新的途径。
Colloidal cadmium chalcogenide nanoplates are two-dimensional semiconductors that have shown great application prospect for light-emitting technologies. Self-trapped state (STS), a special localized state originated from strong electron-phonon coupling (EPC), has great potential in one-step white light luminance owing to its broadband emission linewidth. However, achieving STS in cadmium chalcogenide nanocrystals is extremely challenging due to their intrinic weak EPC nature. By building hybrid superlattice (SL) structures via self-assembly of colloidal CdSe nanoplates (NPLs), we demonstrated an emergence of zone-folded longnitude acoustic phonons (ZFLAP) differ from monodispersed NPLs, and observed a broadband STS emission in spectra range of 450-600 nm. Through femtosecond transient absorption and impulsive vibrational spectroscopy, we revealed that STS is generated in time scale of ~500 fs and is driven by strong coupling of excitons and ZFLAPs with Huang-Rhys parameter as large as ~22.7. Our findings provide a new avenue for generating and manipulating STS emission by artificially designing and building hybrid periodic structures superior to single material optimization.
