High Intensity Low Temperature (HILT) performance of space concentrator GaInP/GaInAs/Ge MJ SCs

In the work, the results of an investigation of GaInP/GaInAs/Ge MJ SCs intended for converting concentrated solar radiation, when operating at low temperatures (down to -190 degrees C) are presented. A kink of the cell I-V characteristic has been observed in the region close to V-oc starting from -20 degrees C at operation under concentrated sunlight. The causes for its occurrence have been analyzed and the reasons for formation of a built-in potential barrier for majority charge carriers at the n-GaInP/n-Ge isotype hetero-interface are discussed. The effect of charge carrier transport in n-GaInP/n-p Ge heterostructures on MJ SC output characteristics at low temperatures has been studied including EL technique

Characterization of the manufacturing processes to grow triple-junction solar cells

A number of important but little-investigated problems connected with III-V/Ge heterostructure in the GaInP/GaInAs/Ge multijunction solar cells grown by MOVPE are considered in the paper. The opportunity for successfully applying the combination of reflectance and reflectance anisotropy spectroscopy in situ methods for investigating III-V structure growth on a Ge substrate has been demonstrated. Photovoltaic properties of the III-V/Ge narrow-band subcell of the triple-junction solar cells have been investigated. It has been shown that there are excess currents in the Ge photovoltaic p-n junctions, and they have the tunneling or thermotunneling character. The values of the diode parameters for these current flow mechanisms have been determined. The potential barrier at the III-V/Ge interface was determined and the origin of this barrier formation during MOVPE heterogrowth was suggested

Capacitance characterization of GaP/n-Si structures grown by PE-ALD

International audienceThin layers of μc-GaP and a-GaP grown on n- type silicon wafers by plasmaenhanced atomic layer deposition at 380 C are characterized by space charge capacitance techniques, C-V profiling and deep level transient spectroscopy (DLTS). Two defect levels with activation energies of 0.30 eV and 0.80 eV were detected by DLTS in the μc-GaP/n-Si structure. Measurements performed on Schottky barriers formed on n-Si after selective etching of the GaPlayer did not reveal any defect level meaning that the observed defects in the μc-GaP/n-Si structure are related to μc-GaP layer

Admittance spectroscopy of InGaNAs layers in solar cells

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Fine-Tuning of the Magnetic Fano Resonance in Hybrid Oligomers via fs-Laser-Induced Reshaping

Various clusters of metallic or dielectric nanoparticles can exhibit sharp Fano resonances originating from at least two modes interference of different spectral width. However, for practical applications such as biosensing or nonlinear nanophotonics, the fine-tuning of the Fano resonances is generally required. Here, we propose and demonstrate a novel type of hybrid oligomers consisting of asymmetric metal-dielectric (Au/Si) nanoparticles with a sharp Fano resonance in the visible range, which has a predominantly magnetic origin. We demonstrate both numerically and experimentally that such hybrid nanoparticle oligomers allow fine-tuning of the Fano resonance via fs-laser-induced melting of Au nanoparticles at the nanometer scale. We show that the Fano resonance wavelength can be changed by fs-laser reshaping very precisely (within 15 nm) being accompanied by a reconfiguration of its profile.This work was financially supported by the Russian Science Foundation (Grant 15-19-30023)

Peculiarities of Doped GaP Layers Growth by Plasma Enhanced Atomic Layer Deposition

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Experimental demonstration of a reconfigurable magnetic Fano resonance in hybrid oligomers

Nanoparticle oligomers made of metallic and/or dielectric nanoparticles are able to support sharp Fano resonances originating from an interference of two resonant modes with different spectral width. For practical applications, it is necessary to have an approach for tuning the Fano resonances of a nanostructure after its fabrication. Herein, we demonstrate a novel type of reconfigurable hybrid metaldielectric (Au-Si) oligomers supporting fine-tunable magnetic Fano resonances. We present an expanded experimental results of the Fano resonance tailoring via femtosecond laser melting of the plasmonic parts at the nanoscale. We believe that our findings pave the way to realization of nanophotonic elements that can be adjusted after their manufacturing.This work was financially supported by the Russian Science Foundation (Grant 15-19-30023)