Influence of PMMA on All-Inorganic Halide Perovskite CsPbBr₃ Quantum Dots Combined with Polymer Matrix.

Lung-Chien Chen,Yu-Shen Dong,Zong-Liang Tseng,Shengyi Yang,Ching-Ho Tien

doi:10.3390/ma12060985

Abstract

The poor stability of CsPbX3 quantum dots (QDs-CsPbX3) under wet conditions is still considered to be a key issue. In order to overcome this problem, this study presents a high molecular weight polymer matrix (polymethylmethacrylate, PMMA) incorporated into the QDs-CsPbBr3 to improve its stability and maintain its excellent optical properties. In this study, the Cs2CO3, PbO, Tetrabutylammonium Bromide (TOAB) powder, oleic acid, and toluene solvent were uniformly mixed and purified to prepare high-quality QDs powders. Then, hexane was used as a dispersing agent for the QD powder to complete the perovskite QDs-CsPbBr3 solution. Finally, a solution with different proportions of quantum dots CsPbBr3 and PMMA was prepared and discussed. In the preparation of thin films, firstly, a thin film with the structure of glass/QD-CsPbBr3/PMMA was fabricated in a glove box using a well-developed QDs-CsPbBr3 solution by changing the ratio of CsPbBr3:PMMA. The material analysis of QDs-CsPbBr3 thin films was performed with photoluminescence (PL), transmittance, absorbance, and transmission electron microscopy (TEM). The structures and morphologies were further examined to study the effect of doped PMMA on perovskite QDs-CsPbBr3.

Highlights

Colloidal quantum dots (QDs) have received extensive attention owing to their high photoluminescence quantum yield (PLQY), tunable emission wavelength, broad band absorption, and narrow emission band [1,2,3,4,5,6,7]
Due to its unique quantum confinement effect [7,8,9], researchers can achieve bandgap tuning by adjusting the emission color of QDs size and content [10,11]. Given these excellent optoelectronic properties, QDs are widely used in solar cells [12,13], light-emitting diodes (LEDs) [14,15], photodetectors [16,17], and lasers [18,19]
The luminance of the QD-CsPbBr3/PMMA film and the laser seem darker than that of the QD-CsPbBr3 film owing to the total reflection effect and QD-CsPbBr3:PMMA film excited by the laser seem darker than that of the QD-CsPbBr3 film

Summary

Introduction

Colloidal quantum dots (QDs) have received extensive attention owing to their high photoluminescence quantum yield (PLQY), tunable emission wavelength, broad band absorption, and narrow emission band [1,2,3,4,5,6,7]. Due to its unique quantum confinement effect [7,8,9], researchers can achieve bandgap tuning by adjusting the emission color of QDs size and content [10,11] Given these excellent optoelectronic properties, QDs are widely used in solar cells [12,13], light-emitting diodes (LEDs) [14,15], photodetectors [16,17], and lasers [18,19]. The use of the high molecular polymer matrix for encapsulation isolates the perovskite QDs from water and oxygen, which is beneficial for the stability of the perovskite QDs, such as PMMA [1], poly(maleic anhydride-alt-1-octadecene) (PMA) [34], or inorganic protective layer QDs due to its high light transmittance and low excitation light

Materials and Methods

Results and Discussion

Conclusions