Organic-Inorganic Hybrid Compounds Based on Lead Halide Units: Preparation from Melts and through Grinding Effects

Abstract

Organic-inorganic hybrid compounds based on lead halide units of the formula (CH 3 NH 3 ) 2 -(CH 3 C 6 H 4 CH 2 NH 3 ) 2 Pb 3 (Br x Y 1−x ) 10 (Y = Cl, I) were prepared from melts, and their optical absorption as well as photoluminescence spectra, before and after grinding the compounds, were investigated. The luminescence of the materials after grinding is strong and is observed with naked eye. By changing the mole fraction (x), the strong photoluminescence in the range from ca. 400 nm to ca. 600 nm could be tuned. These effects indicate that the hybrid compounds are promising materials for potential applications.

Effects of organic moieties on the photoluminescence spectra of perovskite-type tin bromide based compounds

“…The compounds based on C 2 H 5 NH 3 and C 3 H 7 NH 3 do not exhibit strong PL bands, arising from excitonic states, but behave as 1D semiconductors of the type (BC)MX 3 [4][5][6][7].…”

“…Thin deposits were also prepared from solutions (e.g. in acetone) or from melts [7]. In these cases, to minimize the influence of air (oxygen and water), the samples were prepared in an inert (Argon) atmosphere [39].…”

“…The position of the spectral bands occur in the order λ(3D)>λ(2D)>λ(1D), where λ is the wavelength. They can be prepared from their solutions or from melts in single crystal form or in particulate forms (grinding powders, suspensions in several solvents, and dispersions in several matrices) [6,7,[30][31][32][33][34][35][36][37]. In the particulate forms, the products of the reactions are in equilibrium with their precursors [8][9][10], e.g.…”

“…For example, single crystals of (CH 3 NH 3 ) (C 4 H 9 NH 3 ) 2 Pb 2 Br 7 are yellow in color with a weak luminescence. After grinding, they give a powder with a strong green luminescence [6,7,10,11]. This is due to the formation of (SC)PbBr 3 particles [10,11], and the strong luminescence (arround 520 nm ) is arising from the free-excitons of inorganic moiety [10].…”

Room temperature light emitting diode based on 2D hybrid organic-inorganic low dimensional perovskite semiconductor

“…Such examples are HOIS with controllable excitonic peaks covering the ultraviolet-visible region [2], thin film transistor gate materials comparable to amorphous Si [19][20][21] or HOIS exhibiting extremely interesting energy transfer optical phenomena [22,23]. Finally, the 3D and quasi-2D lead halide HOIS have been successfully employed for solar cell applications [24,25].…”