Fluorescence Blinking and Photoactivation of All-Inorganic Perovskite Nanocrystals CsPbBr₃ and CsPbBr₂I

Abstract

Study of the emission behavior of all-inorganic perovskite nanocrystals CsPbBr3 and CsPbBr2I as a function of the excitation power employing fluorescence correlation spectroscopy and conventional techniques reveals fluorescence blinking in the microsecond time scale and photoinduced emission enhancement. The observation provides insight into the radiative and nonradiative deactivation pathways of these promising substances. Because both blinking and photoactivation processes are intimately linked to the charge separation efficiency and dynamics of the nanocrystals, these key findings are likely to be helpful in realizing the true potential of these substances in photovoltaic and optoelectronic applications.

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.…”

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).…”

A Facile Methodology for Engineering the Morphology of CsPbX3 Perovskite Nanocrystals under Ambient Condition

“…Though the journey commenced with the hybrid perovskites, its all-inorganic counterparts (CsPbX 3 ) have also drawn considerable attention in the last couple of years because of their narrow, intense and tunable emission5, low trap state density6, improved stability and charge transport properties78. These characteristics point to the great potential of the CsPbX 3 NCs for future applications691011.…”