Environmentally friendly core-shell quantum dots for light-emitting devices: A computational study

Semiconductor quantum dots (QDs) have been successfully used as light emitters in a variety of applications [1]. CdSe QDs exhibit the best performance in terms of tunable colors in the visible range and luminescence quantum yield. However, they contain a toxic heavy metal and the search for environmentally friendly nanostructured semiconductors is an active field of research. Recently InP based QDs have emerged as a promising alternative [2] to CdSe, although they exhibit broader emission spectra, possibly due to the sensitivity of their electronic structure to small morphological changes. Here we report on a first principle computational study of the structural and opto-electronic properties of InP/Zn(S/Se) core shell QDs. We used DFT with semi-local and hybrid functionals and the QuantumEspresso package (https://www.quantum-espresso.org/). We show that composition and interface morphology are key to achieve narrow emission lines, and we discuss the interplay between quantum confinement and strain in determining the electronic properties of these systems.


[1] Dai, X., Deng, Y., Peng, X., Jin, Y., Adv. Mater. 2017, 29, 1607022.
[2] J. Am. Chem. Soc.2018,140,46,15791-15803