Investigation of the exciton relaxation processes in poly(9,9-dioctylfluorene-co-benzothiadiazole):CsPbI_1.5Br_1.5 nanocrystal hybrid polymer–perovskite nanocrystal blend

Abstract

The emission properties of a hybrid polymer:perovskite nanocrystals (NCs) blend film are investigated, evidencing that the main interaction process is not Förster transfer, but instead bidirectional polymer → NC and NC → polymer charge transfer.

Photon-Energy-Dependent Reversible Charge Transfer Dynamics of Double Perovskite Nanocrystal-Polymer Nanocomposites

“…On the other hand, upon a higher photon-energy UVA (266 nm) excitation, Mn-doped DP NCs presented the PIA and SE features at 560–565 nm, which would disappear in the presence of MDMO-PPV polymers for the nanocomposites. The results indicated charge transfer direction in DP NCs/MDMO-PPV nanocomposites was reversed [ 23 , 41 ]. The reversible charge transfer from Mn-doped DP NCs to MDMO-PPV polymers in the nanocomposites generated the stronger PL of MDMO-PPV polymers.…”

“…Heo et al had achieved an efficient photovoltaic performance in solar cells of three-dimensional composites of TiO 2 /CH 3 NH 3 PbI 3 and complementary well matched polymeric hole conductors [ 19 ]. Future development and optimization of perovskite NC-polymer composites will require a deeper understanding of the critical processes, such as energy transfer and charge transfer [ 20 , 21 , 22 , 23 ]. Introducing CsPbBr 3 NCs into poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly(9,9-di- n -octylfluorenyl-2,7-diyl) composite thin films improved the polymer blend crystallinities, reduced the localized densities of the electronic states, and enhanced energy transfers from the polymer blends to NCs [ 20 ].…”

“…The templating properties of MEH-PPV controlled the self-assembly of CH 3 NH 3 PbI 3 NCs, and those nanocomposites possessed remarkable photovoltaic efficiencies due to charge transfer interface interactions [ 21 ]. In poly(9,9-dioctylfluorene- co -benzothiadiazole) and CsPbI 1.5 Br 1.5 NCs hybrid film, charge transfer both from polymers to the NCs and from the NCs to polymers would take place, and this was expected to be relevant for the development of hybrid organic-perovskite optoelectronic devices [ 23 ].…”