Ultrafast time-resolved photoluminescence spectroscopy following oneand two-photon excitation of ZnO powder is used to gain unprecedented insight into the surprisingly high external quantum efficiency of its “green” defect emission band. The role of exciton diffusion, the effects of reabsorption, and the spatial distributions of radiative and nonradiative traps are comparatively elucidated for ...

The electronic conductivity of Langmuir-Blodgett monolayers of silane-passivated silicon nanoparticles (core diameter 3.86 ( 0.85 nm) was examined by electrochemical measurements within the context of photoirradiation and at controlled temperatures. Temperature dependence of the dark conductivity indicated that the interparticle charge transfer followed a thermal activation mechanism within the...

We combine two scanning electron microscopy techniques to investigate the influence of dislocations on the light emission from nitride semiconductors. Combining electron channeling contrast imaging and cathodoluminescence imaging enables both the structural and luminescence properties of a sample to be investigated without structural damage to the sample. The electron channeling contrast image ...

We reveal substantial luminescence yield heterogeneity among individual subdiffraction grains of high-performing methylammonium lead halide perovskite films by using high-resolution cathodoluminescence microscopy. Using considerably lower accelerating voltages than is conventional in scanning electron microscopy, we image the electron beam-induced luminescence of the films and statistically cha...

To achieve a high fill factor, small diode factor close to 1 is essential. The optical determined by photoluminescence the from neutral zone of solar cell and thus lower bound for factor. Due metastable defects transitions, higher than even at low excitation. Here, influence backside recombination doping level on are studied. First, capacitance simulator (SCAPS) simulations used determine back ...

Modification of hole transporting layers (HTLs) to reduce the interface defects is an important strategy promote extraction and suppress charge recombination for Sb 2 (S,Se) 3 (Antimony selenosulfide) solar cells. Herein, a simple doping method with tetrathiafulvalene derivatives (MeS‐TTF Cyano‐TTF) developed dangling bonding on surface films improve photovoltaic performances The studies show t...

Recently, continuous-wave (CW) lasing was demonstrated at room temperature in quasi-2D perovskites. For 3D films, CW remains challenging. Issues hampering materials include the dependence of (a) distribution carrier energies, (b) buildup photoinduced nonradiative channels, and (c) rates bimolecular versus Auger recombination. We study latter a phase-stable perovskite using high-index substrates...