Sensitized photon avalanche nanothermometry in Pr3+ and Yb3+ co-doped NaYF4 colloidal nanoparticles

Abstract

Photon avalanche (PA) is a highly nonlinear luminescence phenomenon that occurs in lanthanide doped materials. PA exhibits a very steep power law relationship between luminescence intensity and the optical pump power. Due to the mechanism of PA emission, even weak perturbations to the energy looping and energy distribution within excited levels of lanthanide emitters are expected to significantly modify luminescent properties. Therefore, in this work, we experimentally study the impact of temperature (from – 175 to 175 °C, with 25 °C steps) on the sensitized PA emission in NaYF4 nanoparticles co-doped with 15% of Yb3+ and 0.5% of Pr3+ ions under 852 nm pumping wavelength. Significant variations of the PA nonlinearity ( S = 4.5–9), PA gain (from 50 up to 175), and PA threshold (from 100 up to 700 kW/cm2) were observed under temperature rise from – 175 to 175 °C, respectively. The relative temperature sensitivities based on luminescence intensity changes were larger than 1.5% °C–1 in the whole temperature range, reaching the maximal value of 7.5% °C–1 at 0 °C. Moreover, a new thermometric parameter was proposed, namely, the PA pump power threshold, which exhibited over 0.5% °C–1 relative sensitivities in the same wide temperature range. Owing to PA properties, the temperature sensitivity range and the corresponding relative sensitivities may be intentionally tuned by selecting the appropriate pump intensity in respect to the power dependence relationship. These studies not only provide a better understanding of fundamental processes and susceptibility of the sensitized photon avalanche emission to temperature variation, but also show the possibility of using PA materials as sensitive (nano)thermometers.

Understanding Yb3+-sensitized photon avalanche in Pr3+ co-doped nanocrystals: modelling and optimization

“…8 In the latter case Yb 3+ ions work as a sensitizer and establish an energy migration network, hosting the migrating PA mechanism (MPA) 8 or sensitized PA (SPA). 10 These studies confirmed the applicability of the Yb 3+ , Pr 3+ PA system for sub-diffraction imaging 8 and luminescence nanothermometry, 10 as predicted previously. 2,11 However, the mechanisms of sensitization of Pr 3+ avalanche emission by co-doping with Yb 3+ have to be further studied and clarified.…”

“…In the literature, the assignment of emission bands in the 580–620 nm range is ambiguous, as in some reports, they are interpreted as emission from the 3 P 1 level, while others are from the 1 D 2 level. 8,12–17 Here, as also earlier, 10 we assigned the emission at 607 nm to the 3 P 0 → 3 H 6 transition. Considering the emission at 607 nm (16 475 cm −1 ), the energy mismatch is lower for the 3 P 0 → 3 H 6 transition (Δ E = 16 400 cm −1 ) than for the 1 D 2 → 3 H 4 transition (Δ E = 16 800 cm −1 ).…”

All‐Optical Data Processing with Photon‐Avalanching Nanocrystalline Photonic Synapse

“…Avalanching nanocrystals are multifunctional materials, and besides the computing potential, they feature also great and still explored potential for utilization in super‐resolution imaging [ 37 ] and sensing. [ 43,57,58 ] Furthermore, their properties might be tuned and tailored for given application during the synthesis (by adjusting architecture, dopant, or host compositions) or in situ, by proper stimulation (e.g., through variation of excitation powers, length or frequency of the excitation pulses, sequence of the pulses), as we demonstrated in this work.…”

“…[ 50 ] Avalanching nanocrystals are multifunctional materials, and besides the computing potential, they feature also great and still explored potential for utilization in super‐resolution imaging [ 37 ] and sensing. [ 43,57,58 ] Furthermore, their properties might be tuned and tailored for given application during the synthesis (by adjusting architecture, dopant, or host compositions) or in situ, by proper stimulation (e.g., through variation of excitation powers, length or frequency of the excitation pulses, sequence of the pulses), as we demonstrated in this work. The current solution exploits simple, cheap, and widely available semiconductor, fiber pigtailed telecommunication laser diodes from near infrared spectral region at 1064 nm, while the emission from Tm 3+ ions occur at 800 nm falling into visible/NIR spectral region and sensitivity of fast and cheap photodetectors. Both wavelengths fall into transmission windows of conventional optical components.…”