Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom.
Physics Department, Columbia University, New York, New York 10027, USA.
Phys Rev Lett. 2015 Mar 13;114(10):107401. doi: 10.1103/PhysRevLett.114.107401. Epub 2015 Mar 11.
We evaluate binding energies of trions X±, excitons bound by a donor or acceptor charge X^{D(A)}, and overcharged acceptors or donors in two-dimensional atomic crystals by mapping the three-body problem in two dimensions onto one particle in a three-dimensional potential treatable by a purposely developed boundary-matching-matrix method. We find that in monolayers of transition metal dichalcogenides the dissociation energy of X^{±} is typically much larger than that of localized exciton complexes, so that trions are more resilient to heating, despite the fact that their recombination line in optics is less redshifted from the exciton line than the line of X^{D(A)}.
我们通过将二维的三体问题映射到一个在三维势中运动的粒子上，并使用专门开发的边界匹配矩阵方法来处理这个问题，从而评估了二维原子晶体中三体 X±、受施主或受主电荷 X^{D(A)}束缚的激子以及过充电的受主或施主的结合能。我们发现，在过渡金属二卤化物的单层中，X^{±}的离解能通常远大于局域激子复合物的离解能，因此尽管三体在光学中的复合线比 X^{D(A)}的线红移量小，但三体对加热更有抵抗力。
