Recent advances in perovskite-sensitized photon upconversion via triplet-triplet annihilation (TTA) in rubrene have yielded several unanswered questions about the underlying mechanism and processes occurring at the interface. In particular, the near-infrared perovskite emission is not significantly quenched and a rapid reversible "photobleach" of the upconverted emission can be observed under fairly low excitation densities of 3.2 mW/cm. In this contribution, we investigate the perovskite/rubrene interface in more detail and conclude that noncovalent interactions between the organic layer and the perovskite result in surface trap passivation. In addition, band bending results in a space charge region at the perovskite/rubrene interface, which "precharges" the rubrene with holes. Upon initial illumination, electrons can rapidly transfer to the excited triplet state of rubrene, followed by efficient TTA upconversion. As the device is continuously illuminated, the existing holes are consumed and a new equilibrium is reached, resulting in the previously investigated steady-state upconversion efficiency.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jpclett.9b03596 | DOI Listing |
Nanomaterials (Basel)
January 2025
Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China.
A transparent fluoroborosilicate glass ceramic was designed for the controllable precipitation of fluoride nanocrystals and to greatly enhance the photoluminescence of active ions. Through the introduction of BO into fluorosilicate glass, the melting temperature was decreased from 1400 to 1050 °C, and the abnormal crystallization in the fabrication process of fluorosilicate glass was avoided. More importantly, the controlled crystallizations of KZnF and KYbF in fluoroborosilicate glass ceramics enhanced the emission of Mn and Mn-Yb dimers by 6.
View Article and Find Full Text PDFNanophotonics
January 2025
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Sum-frequency generation (SFG) enables the coherent upconversion of electromagnetic signals and plays a significant role in mid-infrared vibrational spectroscopy for molecular analysis. Recent research indicates that plasmonic nanocavities, which confine light to extremely small volumes, can facilitate the detection of vibrational SFG signals from individual molecules by leveraging surface-enhanced Raman scattering combined with mid-infrared laser excitation. In this article, we compute the degree of second order coherence ( (0)) of the upconverted mid-infrared field under realistic parameters and accounting for the anharmonic potential that characterizes vibrational modes of individual molecules.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials Science& Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Lanthanide-doped upconversion luminescent nanoparticles (UCNPs) have garnered extensive attention due to their notable anti-Stokes shifts and superior photostability. Notably, Ho-based UCNPs present a complex energy level configuration, which poses challenges in augmenting their luminescence efficiency. Herein, a rational design strategy was used to enhance the upconversion luminescence intensity of Ho ions by improving the photon absorption ability and energy utilization efficiency.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Huzhou Key Laboratory of Materials for Energy Conversion and Storage, College of Science, Huzhou University, Huzhou 313000, China. Electronic address:
1550 nm-responsive upconversion luminescence (UCL) has attracted increasing attention due to its potential applicability in a new generation of bio-probes and photonic devices. However, regulating multi-color UCL with pump power remains a challenge. In this work, through constructing the coupling between Er and Tm ions and suppressing the energy transfer upconversion process of Er ions, the response of UCL color in Gd(MoO):Er/Tm to pump power is enhanced significantly.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory for High Efficiency Energy Conversion Science and Technology of Henan Province, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng, 475004, P. R. China.
Multimode luminescent materials exhibit tunable photon emissions under different excitation or stimuli channels, endowing them high encoding capacity and confidentiality for anti-counterfeiting and encryption. Achieving multimode luminescence into a stable single material presents a promising but remains a challenge. Here, the downshifting/upconversion emissions, color-tuning persistent luminescence (PersL), temperature-dependent multi-color emissions, and hydrochromism are integrated into Er ions doped CsNaYbCl nanocrystals (NCs) by leveraging shallow defect levels and directed energy migration.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!