Engineering Sr-doping for enabling long-term stable FAPb(1-x)Sr(x)I(3) quantum dots with 100% photoluminescence quantum yield

Engineering Sr-doping for enabling long-term stable FAPb(1-x)Sr(x)I(3) quantum dots with 100% photoluminescence quantum yield

WoS Article

The Pb substitution in quantum dots (PQDs) with lesser toxic metals has been widely searched to be environmentally friendly, and be of comparable or improved performance compared to the lead-perovskite. However, the chemical nature of the lead substitute influences the incorporation mechanism into PQDs, which has not been explored in depth. In this work, we analyzed Sr-doping-induced changes in FAPbI(3) perovskites by studying the optical, structural properties and chemical environment of FAPb(1-x)Sr(x)I(3) PQDs. The substitution of Pb by 7 at% Sr allows us to achieve FAPb(1-x)Sr(x)I(3) PQDs with 100% PLQY, high stability for 8 months under a relative humidity of 40-50%, and T-80 = 6.5 months, one of the highest values reported for halide PQDs under air ambient conditions. FAPb(0.93)Sr(0.07)I(3) PQDs also exhibit photobrightening under UV illumination for 12 h, recovering 100% PLQY at 15 days after synthesis. The suppression of structural defects mediated by Sr-doping decreases the non-radiative recombination mechanism. By attempting to increase the Sr content in PQDs, a mixture of 2D nanoplatelets/3D nanocubes has emerged, caused by a high Pb deficiency during the FAPb(1-x)Sr(x)I(3) synthesis. This contribution gives a novel insight to understand how the suitable/poor Pb substitution achieved through Sr-doping dictates the photophysical properties of PQDs that may be potentially applicable in optoelectronics.

The Pb substitution in quantum dots (PQDs) with lesser toxic metals has been widely searched to be environmentally friendly, and be of comparable or improved performance compared to the lead-perovskite. However, the chemical nature of the lead substitute influences the incorporation mechanism into PQDs, which has not been explored in depth. In this work, we analyzed Sr-doping-induced changes in FAPbI(3) perovskites by studying the optical, structural properties and chemical environment of FAPb(1-x)Sr(x)I(3) PQDs. The substitution of Pb by 7 at% Sr allows us to achieve FAPb(1-x)Sr(x)I(3) PQDs with 100% PLQY, high stability for 8 months under a relative humidity of 40-50%, and T-80 = 6.5 months, one of the highest values reported for halide PQDs under air ambient conditions. FAPb(0.93)Sr(0.07)I(3) PQDs also exhibit photobrightening under UV illumination for 12 h, recovering 100% PLQY at 15 days after synthesis. The suppression of structural defects mediated by Sr-doping decreases the non-radiative recombination mechanism. By attempting to increase the Sr content in PQDs, a mixture of 2D nanoplatelets/3D nanocubes has emerged, caused by a high Pb deficiency during the FAPb(1-x)Sr(x)I(3) synthesis. This contribution gives a novel insight to understand how the suitable/poor Pb substitution achieved through Sr-doping dictates the photophysical properties of PQDs that may be potentially applicable in optoelectronics.

photoluminescence quantum dots, 3D nanocubes

photoluminescence quantum dots, 3D nanocubes

GUALDRON-REYES, A.; MACIAS-PINILLA, D.F.; MASI, S.; ECHEVERRIA-ARRONDO, C.; AGOURAM, S.; MUNOS-SANJOSE, V.; RODRIGUEZ PEREIRA, J.; MACÁK, J.; MORA-SERO, I.

2022

07.02.2021

ROYAL SOC CHEMISTRY

CAMBRIDGE

2050-7534

Journal of Materials Chemistry C

9

5

United Kingdom of Great Britain and Northern Ireland

1555

1566

12

https://pubs.rsc.org/en/content/articlelanding/2021/TC/D0TC04625F