To improve the performance of the polycrystalline thin film devices, it requires a delicate control of its grain structures. As one of the most promising candidates among current thin film photovoltaic techniques, the organic/inorganic hybrid perovskites generally inherit polycrystalline nature and exhibit compositional/structural dependence in regard to their optoelectronic properties. Here, w...

We derive an energy-dependent decay-time distribution function from the multi-exponential decay of the ensemble photoluminescence (PL) of InxGa1-xN/GaN quantum dots (QDs), which agrees well with recently published singleQD time-resolved PL measurements. Using eight-band k·p modelling, we show that the built-in piezoand pyroelectric fields within the QDs cause a sensitive dependence of the radia...

Silicon nanoparticles (Si NPs), exhibiting a strong visible photoluminescence (PL), have found many applications in optoelectronics devices, biomedical tags and flash memories. Chemical etching is a well-known method for synthesizing orange-luminescent, hydride-capped silicon nanoparticles (H/Si NPs). However, a blueshift in emission wavelength occurs when reducing the particle size to exciton ...

Semipolar GaInN/GaN light emitting diodes (LEDs) were investigated as possible candidates for high-brightness devices even in the long wavelength regime. To combine the high material quality known from c-GaN and the advantage of a reduced piezoelectric field, the LED structures were realized on the {1101} side facets of selectively grown GaN stripes that have a triangular shape. Time-resolved a...

Spin relaxation of electrons doped in InP quantum dots was studied by means of luminescence pump-probe and Hanle measurements. Optical pumping makes spins of doped electrons to be oriented in parallel to the helicity of the circularly polarized excitation. The luminescence pump-probe showed the spin orientation of the doped electrons decay on a millisecond time-scale. Hanle measurement clarifie...

Time-resolved photoluminescence (PL) and transient absorption (TA) spectroscopy are conducted in order to get knowledge on the excited state of CdSe nanorods (NR), and to assess the impact of Au nanoparticles (NP) on the carrier dynamics of hybrid Au-CdSe NRs. The decay dynamics measured in solution show an increase of non-radiative decay channels in the presence of Au NPs, whose characteristic...

The dynamics of excitons in individual semiconducting single-walled carbon nanotubes was studied using time-resolved photoluminescence (PL) spectroscopy. The PL decay from tubes of the same (n,m) type was found to be monoexponential, however, with lifetimes varying between less than 20 and 200 ps from tube to tube. Competition of nonradiative decay of excitons is facilitated by a thermally acti...

Charge transfer processes with semiconductor quantum dots (QDs) have generated much interest for potential utility in energy conversion. Such configurations are generally nonbiological; however, recent studies have shown that a redox-active ruthenium(II)-phenanthroline complex (Ru2+-phen) is particularly efficient at quenching the photoluminescence (PL) of QDs, and this mechanism demonstrates g...

The mechanism of lasing in single cadmium sulfide (CdS) nanowire cavities was elucidated by temperature-dependent and time-resolved photoluminescence (PL) measurements. Temperature-dependent PL studies reveal rich spectral features and show that an exciton-exciton interaction is critical to lasing up to 75 K, while an exciton-phonon process dominates at higher temperatures. These measurements t...

Photoluminescence (PL) from GaN substrates fabricated by the ammonothermal growth method was studied in a wide range of temperatures and excitation intensities, both with steady-state time-resolved PL techniques. Three defect-related bands were detected: ultraviolet luminescence band zero-phonon line at 3.27 eV, Zn-related BL1 maximum 2.9 yellow (labeled YL2) 2.3 eV. The YL2 belongs to an unkno...