Temperature-Dependent Emission Kinetics of Colloidal Semiconductor Nanoplatelets Strongly Modified by Stacking

Erdem, Onur
Olutas, Murat
Guzelturk, Burak
Keleştemur, Yusuf
Demir, Hilmi Volkan
We systematically studied temperature-dependent emission kinetics in solid films of solution-processed CdSe nanoplatelets (NPLs) that are either intentionally stacked or nonstacked. We observed that the steady-state photoluminescence (PL) intensity of nonstacked NPLs considerably increases with decreasing temperature, whereas there is only a slight increase in stacked NPLs. Furthermore, PL decay time of the stacked NPL ensemble is comparatively much shorter than that of the nonstacked NPLs, and this result is consistent at all temperatures. To account for these observations, we developed a probabilistic model that describes excitonic processes in a stack using Markov chains, and we found excellent agreement between the model and experimental results. These findings develop the insight that the competition between the radiative channels and energy transfer assisted hole trapping leads to weakly temperature-dependent PL intensity in the case of the stacked NPL ensembles as compared to the nonstacked NPLs lacking strong energy transfer. This study shows that it is essential to account for the effect of NPL stacking to understand their resulting PL emission properties.


Temperature dependence of the energy transfer from amorphous silicon nitride to Er ions
Li, R.; Yerci, Selçuk; Dal Negro, L. (2009-07-27)
The 1.54 mu m photoluminescence and decay time of Er-doped amorphous silicon nitride films with different Si concentrations are studied in the temperature range of 4 to 320 K. The temperature quenching of the Er emission lifetime demonstrates the presence of nonradiative trap centers due to excess Si in the films. The temperature dependence and the dynamics of the energy coupling between amorphous silicon nitride and Er ions are investigated at different temperatures using two independent methods, which dem...
Thermally Induced Phase Transition and Defect-Assisted Nonlinear Absorption and Optical Limiting in Nanorod Morphology V2O5 Thin Films
Pepe, Yasemin; Tutel, Yusuf; Yildiz, Elif Akhuseyin; Karatay, Ahmet; Ünalan, Hüsnü Emrah; Elmalı, Ayhan (2021-01-01)
© 2021 Wiley-VCH GmbHVanadium pentoxide (V2O5) thin films are greatly favorable materials for optoelectronic applications due to their broad optical bandgap and considerable thermal and chemical stability. Herein, the influence of thermal treatment on the microstructure related to the nonlinear optical, optical limiting, and phase transition behaviors of V2O5 thin films produced via ultrasonic spray deposition method onto FTO/glass substrates is systematically examined by Z-scan experiments. Homogenous and ...
Temperature dependent band gap in SnS2xSe(2-2x) (x=0.5) thin films
Delice, S.; Isik, M.; Gullu, H. H.; Terlemezoglu, M.; Surucu, O. Bayrakli; Hasanlı, Nızamı; Parlak, Mehmet (Elsevier BV, 2020-08-01)
Structural and optical properties of SnS2xSe(2-2x) thin films grown by magnetron sputtering method were investigated for composition of x = 0.5 (SnSSe) in the present study. X-ray diffraction, energy dispersive X-ray spectroscopy, atomic force microscopy and scanning electron microscopy methods were used for structural characterization while temperature-dependent transmission measurements carried out at various temperatures in between 10 and 300 K were accomplished for optical investigations. X-ray diffract...
Energy transfer and 1.54 mu m emission in amorphous silicon nitride films
Yerci, Selçuk; Kucheyev, S. O.; VAN BUUREN, TONY; Basu, S. N.; Dal Negro, L. (2009-07-20)
Er-doped amorphous silicon nitride films with various Si concentrations (Er:SiNx) were fabricated by reactive magnetron cosputtering followed by thermal annealing. The effects of Si concentrations and annealing temperatures were investigated in relation to Er emission and excitation processes. Efficient excitation of Er ions was demonstrated within a broad energy spectrum and attributed to disorder-induced localized transitions in amorphous Er:SiNx. A systematic optimization of the 1.54 mu m emission was pe...
Effective theory of interacting fermions in shaken square optical lattices
Keleş, Ahmet; Liu, W. Vincent (2017-06-01)
We develop a theory of weakly interacting fermionic atoms in shaken optical lattices based on the orbital mixing in the presence of time-periodic modulations. Specifically, we focus on fermionic atoms in a circularly shaken square lattice with near-resonance frequencies, i.e., tuned close to the energy separation between the s band and the p bands. First, we derive a time-independent four-band effective Hamiltonian in the noninteracting limit. Diagonalization of the effective Hamiltonian yields a quasienerg...
Citation Formats
O. Erdem, M. Olutas, B. Guzelturk, Y. Keleştemur, and H. V. Demir, “Temperature-Dependent Emission Kinetics of Colloidal Semiconductor Nanoplatelets Strongly Modified by Stacking,” JOURNAL OF PHYSICAL CHEMISTRY LETTERS, vol. 7, no. 3, pp. 548–554, 2016, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/92243.