Point defects in high-purity GaN layers grown by hydride vapor phase epitaxy are studied by steady-state and time-resolved photoluminescence (PL). The electron-capture coefficients for defects responsible for the dominant defect-related PL bands in this material are found. The capture coefficients for all the defects, except for the green luminescence (GL1) band, are independent of temperature....

Magneto-optical and time-resolved photoluminescence (PL) spectroscopies are employed to evaluate electronic structure of a bound exciton (BX) responsible for the 3.364 eV line (labeled as I1) in bulk ZnO. From timeresolved PL spectroscopy, I1 is concluded to originate from the exciton ground state. Based on performed magneto-PL studies, the g-factors of the involved electron and hole are determ...

We have synthesized core/shell NaGdF(4):Nd(3+)/NaGdF(4) nanocrystals with an average size of 15 nm and exceptionally high photoluminescence (PL) quantum yield. When excited at 740 nm, the nanocrystals manifest spectrally distinguished, near-infrared to near-infrared (NIR-to-NIR) downconversion PL peaked at ∼900, ∼1050, and ∼1300 nm. The absolute quantum yield of NIR-to-NIR PL reached 40% for co...

Quantum and dielectric confinement effects in 2D hybrid perovskites create excitons with a binding energy exceeding 150 meV. We exploit the large exciton binding energy to study exciton and carrier dynamics as well as electron-phonon coupling in hybrid perovskites using absorption and photoluminescence (PL) spectroscopies. At temperatures below 75 K, we resolve splitting of the excitonic absorp...

This paper addresses the problem of selecting measurement data types suitable for image reconstruction in optical tomography. The principal problem is the necessity to simultaneously reconstruct both the absorption and scatter distribution within an object. This can lead to ambiguities between these two parameters, and result in cross-talk and image artefact. A single-perturbation test problem ...

Solution-processed hybrid perovskite of CH3NH3PbI3 (MAPbI3) exhibits an abnormal luminescence behavior at around the tetragonal-orthorhombic phase transition temperature. The combination of time resolved photoluminescence (PL), variable excitation power PL, and variable-temperature X-ray diffraction (XRD) allows us to clearly interpret the abnormal luminescence features in the phase transition ...

Two-dimensional (2D) colloidal anisotropic CdSe nanoplatelets (NPLs) have attracted a great deal of attraction within recent years. Their strong thickness-dependent absorption and emission spectra exhibit significant differences from those of other shaped CdSe nanocrystals (NCs) due to a unique atomically flat morphology. Based on their dielectric confinement effect and the large confinement en...

Pure and europium (Eu(3+)) doped ZrO(2) synthesized by an oil-in-water microemulsion reaction method were investigated by in situ and ex situ X-ray diffraction (XRD), ex situ Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), steady state and time-resolved photoluminescence (PL) spectroscopies. Based on the Raman spectra excited at three different wavelengths i.e. 488...

We investigate the photoluminescence (PL) spectra and the time-resolved PL decay process from colloidal quantum dots on SiN/SiO2 wet etched via BOE (HF:NH4F:H2O). The spectrum displays multi-peak shapes that vary with irradiation time. The evolution of the spectral peaks with irradiation time and collection angle demonstrates that the strong coupling of the charged-exciton emission to the leaky...

We observed the optically forbidden energy transfer between cubic CuCl quantum dots coupled via an optical near-field interaction using time-resolved near-field photoluminescence (PL) spectroscopy. The energy transfer time and exciton lifetime were estimated from the rise and decay times of the PL pump-probe signal, respectively. We found that the exciton lifetime increased as the energy transf...