相关论文: Disentangling nonradiative recombination processes…
We demonstrate the critical role of surface recombination in mixed-cation, mixed-halide perovskite, FA0.83Cs0.17Pb(I0.85Br0.15)3. By passivating non-radiative defects with the polymerizable Lewis base (3-aminopropyl)trimethoxysilane (APTMS)…
Phase-change materials based on Ge-Sb-Te alloys are widely used in industrial applications such as nonvolatile memories, but reaction pathways for crystalline-to-amorphous phase-change on picosecond timescales remain unknown. Femtosecond…
Over the last two decades, intensive research efforts have been devoted to the suppressions of photoluminescence (PL) blinking and Auger recombination in metal-chalcogenide nanocrystals (NCs), with significant progresses being made only…
The photoluminescence (PL), color purity, and stability of lead halide perovskite nanocrystals depend critically on the surface passivation. We present a study on the temperature dependent PL and PL decay dynamics of lead bromide perovskite…
Muons, as a bulk probe of materials, have been used to study the depth profile of charge carrier kinetics in Si wafers by scanning the muon implantation depth. The photoexcited muon spin spectroscopy technique can optically generate excess…
The method of software analysis of high-resolution TEM images using the peak pairs algorithm in combination with Raman spectroscopy was employed to study lattice deformations in Ge/Si(001) structures with low-temperature Ge quantum dots. It…
Phase change alloys have seen widespread use from rewritable optical discs to the present day interest in their use in emerging neuromorphic computing architectures. In spite of this enormous commercial interest, the physics of carriers in…
The issue of the quantitative analysis of time-resolved photoluminescence experiments is addressed by developing and describing two approaches for determination of unimolecular lifetime, bimolecular recombination coefficient, and…
GaN nanowires grown by molecular beam epitaxy generally suffer from dominant nonradiative recombination, which is believed to originate from point defects. To suppress the formation of these defects, we explore the synthesis of GaN…
GaN/AlN nanowire heterostructures can display photoluminescence (PL) decay times on the order of microseconds that persist up to room temperature. Doping the GaN nanodisk insertions with Ge can reduce these PL decay times by two orders of…
We report on low-temperature photoconductivity (PC) in n-PbTe(Ga) epitaxial films prepared by the hot-wall technique on <111>-BaF_2 substrates. Variation of the substrate temperature allowed us to change the resistivity of the films from…
For Si and Ge nanocrystals (NCs) embedded in wide band-gap matrices, Auger recombination (AR) and carrier multiplication (CM) lifetimes are computed exactly in a three-dimensional real space grid using empirical pseudopotential wave…
We report a photoluminescence (PL) and transient reflection spectroscopy study of exciton dynamics in monolayer transition transition-metal dichalcogenides (TMDs). PL saturation in monolayer MoSe2 occurs an excitation intensity more than…
Many fundamental processes of structural changes at surfaces occur on a pico- or femtosecond time scale. In order to study such ultra-fast processes, we have combined modern surface science techniques with fs-laser pulses in a pump-probe…
Carrier multiplication is a non-radiative recombination mechanism that leads to the generation of two or more electron-hole pairs after absorption of a single photon. By reducing the occurrence of dissipative effects, this process can be…
Intermediate band photovoltaics hold the promise of being highly efficient and cost effective photovoltaic cells. Intermediate states in the band gap, however, are known to facilitate nonradiative recombination. Much effort has been…
For potentially wider applications of ceramics with dislocation-tuned mechanical and functional properties, it is pertinent to achieve dislocation engineering in polycrystalline ceramics. However, grain boundaries (GBs) in general are…
Global optimization of transition paths in complex atomic scale systems is addressed in the context of misfit dislocation formation in a strained Ge film on Si(001). Such paths contain multiple intermediate minima connected by minimum…
The ability to reduce energy loss at semiconductor surfaces through passivation or surface field engineering has become an essential step in the manufacturing of efficient photovoltaic (PV) and optoelectronic devices. Similarly, surface…
A metallic surface is realized on stoichiometric and insulating (100) SrTiO$_3$ by Ar$^+$ - ion irradiation. The sheet carrier density and Hall mobility of the layer are $\sim$$4.0$ $\times$ $10^{14}$ $/cm^2$ and $\sim$$2$ $\times$ $10^3$…