Single Cesium Lead Halide Perovskite Nanocrystals at Low Temperature: Fast Single-Photon Emission, Reduced Blinking, and Exciton Fine Structure

Abstract

Metal-halide semiconductors with perovskite crystal structure are attractive due to their facile solution processability, and have recently been harnessed very successfully for high-efficiency photovoltaics and bright light sources. Here, we show that at low temperature single colloidal cesium lead halide (CsPbX3, where X = Cl/Br) nanocrystals exhibit stable, narrow-band emission with suppressed blinking and small spectral diffusion. Photon antibunching demonstrates unambiguously nonclassical single-photon emission with radiative decay on the order of 250 ps, representing a significant acceleration compared to other common quantum emitters. High-resolution spectroscopy provides insight into the complex nature of the emission process such as the fine structure and charged exciton dynamics.

Excitation Intensity Dependence of Photoluminescence Blinking in CsPbBr3 Perovskite Nanocrystals

“…Several other reports have examined PL blinking in CsPbX 3 NCs of size similar to the NCs presented here, including at different excitation intensities, but the reported results have varied considerably. [30][31][32][33]51 Flickering of the PL has been reported, where the PL blinks between a bright state and a dim but not off state with short dim-time bursts of <60 ms, 31 while binary on−off blinking has also been reported. 33 Photoactivation at higher powers has been observed and attributed to light-induced structural reorganization 32 as well as rapid PL bleaching even at low excitation intensities.…”

Colloidal lead halide perovskite nanocrystals: synthesis, optical properties and applications

“…Some studies have shown that CsPbX 3 (where X = Cl/Br) NCs seem to be less prone to blinking and display stable emission at low temperatures. 105 Nevertheless, it seems as the problems associated with photostability and blinking of perovskite NCs are largely similar to those of conventional semiconductor quantum dots. Therefore, resolving the issue by applying the methodologies developed over the years for semiconductor NCs is of a great relevance.…”

Polymer-Enhanced Stability of Inorganic Perovskite Nanocrystals and Their Application in Color Conversion LEDs

“…[1][2][3][4] Of high interest are their remarkable optical properties such as non-linear absorption, stimulated emission and blinking behavior. 2,[5][6][7] Compared to classical Cd-based chalcogenide quantum dots (QDs), CsPbX 3 (X = Cl, Br, I) offer a very broad and easily adjustable composition versatility together with ample options for shape control, which allow tuning of their emission wavelength throughout the whole visible spectrum. [8][9][10][11][12][13][14] Among other applications, such highly luminescent and spectrally tunable NCs are ideally suited to produce monochromatic and white LEDs (WLEDs).…”