IBS Publications Repository: Ultrastable PbSe nanocrystal quantum dots via in situ formation of atomically thin halide adlayers on PbSe(100)

cncr's photo.

Ultrastable PbSe nanocrystal quantum dots via in situ formation of atomically thin halide adlayers on PbSe(100)

Cited 118 time in webofscience

Cited 120 time in

1,216 Viewed 259 Downloaded

Title: Ultrastable PbSe nanocrystal quantum dots via in situ formation of atomically thin halide adlayers on PbSe(100)

Author(s): Woo J.Y.; Jae-Hyeon Ko; Song J.H.; Kim K.; Choi H.; Yong-Hyun Kim; Lee D.C.; Jeong S.

Subject: Field effect transistors, ; Passivation, ; Semiconductor quantum dots, ; Ambient conditions, ; DFT calculation, ; In-situ formations, ; Lead selenide, ; Nanocrystal quantum dots, ; Optoelectronic applications, ; Optoelectronic characteristics, ; PbSe nanocrystals, ; Semiconducting lead compounds

Journal: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, v.136, no.25, pp.8883 - 8886

Abstract: The fast degradation of lead selenide (PbSe) nanocrystal quantum dots (NQDs) in ambient conditions impedes widespread deployment of the highly excitonic, thus versatile, colloidal NQDs. Here we report a simple in situ post-synthetic halide salt treatment that results in size-independent air stability of PbSe NQDs without significantly altering their optoelectronic characteristics. From TEM, NMR, and XPS results and DFT calculations, we propose that the unprecedented size-independent air stability of the PbSe NQDs can be attributed to the successful passivation of under-coordinated PbSe(100) facets with atomically thin PbX2 (X = Cl, Br, I) adlayers. Conductive films made of halide-treated ultrastable PbSe NQDs exhibit markedly improved air stability and behave as an n-type channel in a field-effect transistor. Our simple in situ wet-chemical passivation scheme will enable broader utilization of PbSe NQDs in ambient conditions in many optoelectronic applications. © 2014 American Chemical Society.