Figure 23.

(a) Room-temperature VSL measurements of optical gain in 4 ML-CdSe-NPL film using excitation fluences ranging between 17 and 910 μJ cm^–2 (150 fs, 400 nm pulsed excitation). At the highest pump level, the modal gain coefficient reaches a very high value of 6300 cm^–1. Adapted with permission from ref (157). Copyright 2019 American Chemical Society. (b) A solid-state film made of 11 layers of 4-ML CdSe NPLs with a Cd_0.25Zn_0.75S alloyed shell. This image illustrates that NPLs are capable of forming very dense solids, which helps boost optical gain. Adapted with permission from ref (153). Copyright 2020 American Chemical Society.