Near-unity photoluminescence quantum yield in inorganic perovskite nanocrystals by metal-ion doping.

Ghada H Ahmed,Jun Yin,Osman M Bakr,Omar F Mohammed

doi:10.1063/1.5131807

Abstract

The luminescence and charge transport properties of inorganic CsPbX3 perovskite nanocrystals (NCs) make them attractive candidates for various optoelectronic applications, such as lasing, X-ray imaging, light communication, and light-emitting diodes (LEDs). However, to realize cutting-edge device performance, high-quality NCs with high photoluminescence quantum yields (PLQYs) are essential. Therefore, substantial efforts and progress have been made to attain superior design/engineering and optimization of the inorganic NCs with a focus on surface quality, reduced nonradiative charge carrier recombination centers, and improved colloidal stabilities. Metal-ion doping has been proven to have a robust influence on the electronic band structure, PL behavior, and charge carrier recombination dynamics. Thus, in this perspective, we summarize the recent progress of the significant impact of metal cation doping on the optical properties, including the PL enhancement of CsPbCl3, CsPbBr3, and CsPbI3 perovskite NCs. Moreover, we shed light on the mechanism behind such improved properties. We conclude by recommending possible aspects and strategies to be further explored and considered for better utilization of these doped NCs in thin-film optoelectronic and energy conversion devices.

Highlights

We summarize the recent studies on the B-site metal ion doping of CsPbX3 (X = Cl, Br, and I) NCs that lead to the improved optical characteristics
We present the recent works and progress made on the metal doping of CsPbCl3, CsPbBr3, and CsPbI3 and give an overview of the current understanding of the inherent doping mechanisms that lead to PL enhancement and how dopants control the optical properties of inorganic perovskite materials
Gd3+ doping (10 mol. %) of α-CsPbI3 led to an increase in both the photoluminescence quantum yields (PLQYs) from 70% to 80% and the fluorescence lifetime from 47.4 ns to 64.4 ns, which stem from the promoted radiative recombination due to the reduced defect state density

Summary

INTRODUCTION

. .) into perovskite NCs can generate a high PLQY—approaching near-unity in some cases—of metal ion-related emission as a result of the efficient energy transfer from the perovskite NC host to the dopants.. . .) into perovskite NCs can generate a high PLQY—approaching near-unity in some cases—of metal ion-related emission as a result of the efficient energy transfer from the perovskite NC host to the dopants.58–62 Another variety of monovalent, divalent, and heterovalent metal ion dopants (Ni2+, Cd2+, Cu2+, Ca2+, Sr2+, Na+, Ce3+, and Sb3+) has led to the improved PLQY of the perovskite NCs without introducing new emission bands.. It was noted that some dopants (i.e., Bi3+, Al3+, and Ag+) tend to introduce trap states in the bandgap that quench the photoluminescence.67–69 Despite these impressive strides in the area of perovskite doping, the exact influence of dopant ions on the optical properties and their behavior inside the perovskite matrix remains unclear and hard to predict.. We discuss the present limitations and challenges to be solved to further expand the potential integration of doped perovskite NCs into optoelectronic devices for better efficiency and operational stability

Metal-ion doped CsPbCl3 nanocrystals

Metal-ion doped CsPbBr3 nanocrystals

Metal-ion doped CsPbI3 nanocrystals

Findings

CONCLUSION AND REMARKS