Particle Shape Effects on Optical Absorption in Semiconductor Colloids

Abstract
The absorption spectrum of small MoS2 particles in colloidal dispersions differs significantly from that of bulk material. In particular the amplitude and position of exciton absorption peaks shifts when small particles are suspended in a dielectric fluid. Our results are compared with predictions of a Maxwell-Garnett effective medium theory for ellipsoidal particles. We find that particle aspect ratio is an important parameter for interpreting these changes.