High quantum efficiency and stability of biohybrid quantum dots nanojunctions in bacteriophage-constructed perovskite

Abstract

Forming heterojunctions is a traditional approach for improving the performance of semiconducting nanomaterials. However, using a biological nanostructure to achieve such a goal has rarely been studied. Here we showcase a novel biohybrid junction comprising a functional nanobiomaterial (bacteriophage) and a semiconductor nanomaterial (perovskite quantum dots). We found that M13 bacteriophage, genetically modified to bear increased negative charges, could assist the growth of cubic cesium lead bromide (CsPbBr3) perovskite quantum dots with a size of 13.25 ± 2.69 nm. The M13 bacteriophage further functioned as a scaffold for the assembly of the formed CsPbBr3 quantum dots into a bacteriophage-perovskite biohybrid with a photoluminescence quantum yield of 40.1%, 2.99-fold higher than that of conventional CsPbBr3 quantum dots (13.4%). In addition, compared to the conventional perovskite quantum dots, the perovskite quantum dots in the bacteriophage-based biohybrids exhibited a decreased full width at half maximum (FWHM) of the photoluminescence, indicating that the biohybrids are a better color gamut for light-emitting device applications. Such high optical performance arose from the ordered arrangement of the quantum dots by the bacteriophage, which further affected the charge density due to the interaction between the bacteriophage and CsPbBr3 surface. The materials lifetime of the M13 bacteriophage-assisted perovskite quantum dots was also 1.76 times greater than that of the conventional counterparts without the assistance of bacteriophages due to the reduced valence energy level in the biohybrids. The experiment using bacteriophage with artificially increased surface charge density through genetic manipulation proved our assumption that the surface charge density of the bacteriophage contributes to the stabilization of perovskite quantum dots. The light-emitting diode (LED) with perovskite quantum dots assembled and functionalized by bacteriophage exhibited a 17-fold higher maximum luminance than that of conventional CsPbBr3 quantum dots. This work demonstrates a novel nanobiotechnological approach to the production and assembly of perovskite quantum dots for light-emitting applications.