New technique could improve optical devices

The orientation of light emission

The angular distribution of light emission from monolayer MoS2, left, closely matches the theoretical calculations for in-plane oriented emitters, right, indicating that light emission from MoS2 originates from in-plane oriented emitters. Credit: Zia lab/Brown University

A multi-university research team has used a new spectroscopic method to gain a key insight into how light is emitted from layered nanomaterials and other thin films. The technique, called energy-momentum spectroscopy, enables researchers to look at the light emerging from a thin film and determine whether it is coming from emitters oriented along the plane of the film or from emitters oriented perpendicular to the film. Knowing the orientations of emitters could help engineers make better use of thin-film materials in optical devices like LEDs or solar cells.