AVS 63rd International Symposium & Exhibition
    Plasma Science and Technology Tuesday Sessions
       Session PS+2D-TuA

Invited Paper PS+2D-TuA3
Plasma Prize Talk: Nonthermal Plasma Synthesis of Nanocrystal Materials

Tuesday, November 8, 2016, 3:00 pm, Room 104B

Session: Plasma Processing for Nanomaterials and 2D Materials
Presenter: Uwe Kortshagen, University of Minnesota
Authors: N.J. Kramer, University of Minnesota
K. Schramke, University of Minnesota
T. Chen, University of Minnesota
H. Fu, University of Minnesota
S. Ehrenberg, University of Minnesota
K. Reich, University of Minnesota
B. Shklovskii, University of Minnesota
U.R. Kortshagen, University of Minnesota
Correspondent: Click to Email
Nonthermal plasma synthesis of nanocrystals is particularly suited for covalently bonded materials that require high temperatures to be produced with good crystallinity. Several years ago, we showed that plasma produced silicon nanocrystals are capable of high-efficiency photoluminescence, different from bulk silicon material. More recently, the capability of nonthermal plasmas to produce substitutionally doped nanocrystal materials has attracted attention, as substitutional doping had presented a significant challenge both for liquid and gas phase synthesis due to effects such as self-purification.

This presentation discusses the physics of plasma synthesis process. High photoluminescense quantum yields are achieved by careful surface functionalization through grafting alkene ligands to the nanocrystal surfaces. We also discuss the substitutional doping of silicon nanocrystals with boron and phosphorous using a nonthermal plasma technique. While the synthesis approach is identical in both cases, the activation behavior of these two dopants is found to be dramatically different. Finally, we present some experimental work on transport in films of highly phosphorous-doped nanocrystals, which indicates the approach to the metal-to-insulator transition.

This work was supported in part by the NSF Materials Research Science and Engineering Center under grant DMR-1420013, the DOE Energy Frontier Research Center for Advanced Solar Photophysics, and the Army Office of Research under MURI grant W911NF-12-1-0407.