论文标题
通过二维CRPS4中的自旋翻转的光致发光路径分叉
Photoluminescence Path Bifurcations by Spin Flip in Two-Dimensional CrPS4
论文作者
论文摘要
协调铬（III）的超薄分层晶体不仅有望成为二维（2D）磁体，而且由于远距离自旋相关性和CR3+离子的高旋转激发态之间的有效过渡而成为2D近红外（NIR）发射器。在这项研究中，我们报告了CRPS4的双波段NIR光致发光（PL），并表明其激子发射分叉成荧光和磷光，这取决于厚度，温度和缺陷密度。除了光谱分支外，在CR（III）的三级动力学模型中，可以很好地描述PL瞬变的Biexpenential衰减，也可以很好地描述。从本质上讲，PL分叉由从低旋转状态到高旋转状态的激活的反向间间交叉横断，并且由于表面局部定位的缺陷，对于较薄的2D样品，过渡屏障变得较低。我们的发现可以推广到协调金属的2D固体，并且对于实现新颖的磁化功能和设备而言将很有价值。
Ultrathin layered crystals of coordinated chromium(III) are promising not only as two-dimensional (2D) magnets but also as 2D near-infrared (NIR) emitters owing to long-range spin correlation and efficient transition between high and low-spin excited states of Cr3+ ions. In this study, we report on dual-band NIR photoluminescence (PL) of CrPS4 and show that its excitonic emission bifurcates into fluorescence and phosphorescence depending on thickness, temperature and defect density. In addition to the spectral branching, the biexponential decay of PL transients, also affected by the three factors, could be well described within a three-level kinetic model for Cr(III). In essence, the PL bifurcations are governed by activated reverse intersystem crossing from the low to high-spin states, and the transition barrier becomes lower for thinner 2D samples because of surface-localized defects. Our findings can be generalized to 2D solids of coordinated metals and will be valuable in realizing novel magneto-optic functions and devices.
