Nanoscale physics

Influence of the medium on the optical properties of CsPbBr3 nanocrystals
Skrypnyk T.V., Bespalova I.I., Viagin O.G., Sorokin A.V., Yefimova S.L.
Yu.V. Malyukin Nanostructured Materials Department, Institute for Scintillation Materials NAS of Ukraine. 
Nauky ave., Kharkiv-61072, Ukraine. 
E-mail: skrypnyk_tamara@isma.kharkov.ua

	The development of scintillation materials science and modern applications of scintillation detectors requires a reduction in the cost of the process of manufacturing scintillators simultaneously with more stringent requirements in terms of their performances. It is known that nanosized halide perovskite crystals with the general formula CsPbX3 (where X is Cl, Br, or I) can become a material that can satisfy all these requirements. Obtaining perovskite nanocomposite materials with unique optical properties are being actively studied [1, 2].
	It should be noted that halide perovskites have such a disadvantage as hygroscopicity. To solve this problem, such halide nanocrystals can be incorporated into nanoporous matrices such as anodic aluminum oxide (AAO) or polymethyl methacrylate (PMMA) films.
	Colloidal nanocrystals of CsPbBr3 perovskite were obtained using the LARP strategy. The creation of solid samples of perovskite nanocrystals by their incorporation into PMMA films and AAO matrices has been carried out. Their optical parameters were determined and compared (Tab.1).

	Table 1. The decay time of samples.
Samples	τaverage, ns	
A colloidal solution of CsPbBr3	in chloroform	3,870	
	in toluene	5,192	
Nanocrystals of CsPbBr3 in AAO	1,434	
Nanocrystals of CsPbBr3 in PMMA	3,561	

1.	Q. Chen, J. Wu, X. Ou, et al, All-inorganic perovskite nanocrystal scintillators // Nature.-2018.-561.-P. 88–93.
2.	Y. Zhang, R. Sun, X. Ou, et al, Metal Halide Perovskite Nanosheet for X-ray High-Resolution Scintillation Imaging Screens // ACS Nano.-2019.-13.-P 2520–2525