Konstantin Gartsman

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CH3NH3PbI3-based solar cells were characterized with electron beam-induced current (EBIC) and compared to CH3NH3PbI(3-x)Clx ones. A spatial map of charge separation efficiency in working cells shows p-i-n structures for both thin film cells. Effective diffusion lengths, LD, (from EBIC profile) show that holes are extracted significantly more efficiently(More)
Developments in organic-inorganic lead halide-based perovskite solar cells have been meteoric over the last 2 years, with small-area efficiencies surpassing 15%. We address the fundamental issue of how these cells work by applying a scanning electron microscopy-based technique to cell cross-sections. By mapping the variation in efficiency of charge(More)
The mechanical properties of materials and particularly the strength are greatly affected by the presence of defects; therefore, the theoretical strength ( approximately 10% of the Young's modulus) is not generally achievable for macroscopic objects. On the contrary, nanotubes, which are almost defect-free, should achieve the theoretical strength that would(More)
Variable temperature electron beam induced current technique was employed for the profiling of ZnO p-n homojunctions and the extraction of minority electron diffusion length values in the Sb-doped p-type ZnO region. A thermally induced increase for diffusion length of minority electrons was determined to have an activation energy of ϳ145 meV. The latter(More)
The effects of solid-state electron injection on the peak amplitude and decay time of photosignal in a ZnO-based homojunction UV photodiode were studied using temporal photoresponse measurements under femtosecond pulses of 355 nm radiation. The injection of about 50 C of charge, carried out by applying forward bias to the junction, resulted in a nearly(More)
Multiple-junction structures were formed, on a microscopic scale, at room temperature, by the application of a strong electric field across originally homogeneous crystals of the ternary chalcopyrite semiconductor CulnSe(2). After removal of the electric field, the structures were examined with electron beam-induced current microscopy and their(More)
The lattice parameter of nanocrystalline ceria films prepared by sputtering was monitored as a function of annealing temperature. Within the temperature range of 150-420 degrees C, an equilibrium with atmospheric oxygen is established within a few hours, whereas grain growth does not occur. On the basis of the experimental results and analysis of literature(More)
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