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We critically examine how two processing steps commonly applied in the preparation of cadmium telluride (CdTe)-based solar cells, i.e., the cadmium chloride treatment and the subsequent stepwise bromine/methanol wet etching process, impact the structural and optical properties of polycrystalline CdTe thin-films. In particular, drawing upon a conjuncture of photothermal deflection spectroscopy and spectroscopic ellipsometry experimental results, we determine the spectral dependence of the optical absorption coefficient, α(E), over the photon energy range from 1.1 to 2.0 eV for samples of rf sputtered (RFS) and close space sublimation (CSS) CdTe. The impact of these processing steps on shaping the grazing incidence x-ray diffraction pattern is also examined. We extend the analysis to devices through interpretation of the spectral dependence of the external quantum efficiency associated with two cadmium chloride treated CdTe-based solar cells. The cells are comparably prepared with the exception of the absorber, one by RFS and the other by CSS. Through the use of our results for the thin-film CdTe optical functions and a model for the solar cell multilayer structure, we simulate the resultant external quantum efficiency spectrum. Through a critical contrast with the corresponding solar cell acquired experimental results, we glean insights into the carrier trapping and recombination processes that occur within the two types of CdTe absorbers. [ABSTRACT FROM AUTHOR]

We examine the dependence of the crystalline volume fraction on the mean crystallite size for hydrogenated nanocrystalline silicon based photovoltaic solar cells; this work builds upon an earlier study by Schmidt et al. (Mater. Res. Soc. Symp. Proc. 1536 (2013)). For each photovoltaic solar cell considered, the X-ray diffraction and Raman spectra are measured. Through the application of Scherrer's equation, the X-ray diffraction results are used to determine the corresponding mean crystallite sizes. Through peak decomposition, the Raman results are used to estimate the corresponding crystalline volume fraction. Plotting the crystalline volume fraction as a function of the mean crystallite size, it is found that larger mean crystallite sizes tend to favor reduced crystalline volume fractions. The ability to randomly pack smaller crystallites with a greater packing fraction than their larger counterparts was suggested as a possible explanation for this observation. PACS Nos.: 61.05.cp, 78.30.Ly, 68.37.-d. Nous examinons la dependance de la fraction cristalline en volume sur la grosseur moyenne des cristallites (grains) dans des cellules solaires a base de silicium nanocristallin hydrogene. Ce travail est base sur une etude anterieure par Schmidt et al. (Mater. Res. Soc. Symp. Proc. 1536 (2013)). Nous mesurons la diffraction X et le spectre Raman pour chaque cellule photovoltaique etudiee. Par l'equation de Scherrer, les mesures de diffraction X permettent de determiner la grosseur des cristallites. Via une decomposition spectrale, les resultats Raman nous permettent d'estimer la fraction cristalline en volume correspondante. Le graphique de la fraction volumique en fonction de la grosseur des cristallites indique que de plus grosses crystallites correspondent a une plus petite fraction cristalline en volume. La capacite d'entasser au hasard de plus petites cristallites avec un plus grand coefficient de tassement que ce qu'il est possible d'obtenir avec des cristallites plus grosses, est une explication possible de ce resultat. [Traduit par la Redaction], 1. Introduction As a material for thin-film photovoltaic solar cell device applications, hydrogenated nanocrystalline silicon (nc-Si:H) offers a number of inherent advantages when contrasted with the case of hydrogenated amorphous [...]

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Multilevel mixing of 1s and 2s states of excitons in quantum-well semiconductors is examined.

The optical properties and hetero junction band alignment are presented for fully coherent strain-compensated InAsxP1-x/GayIn1-yP multilayer structures grown on InP(001).

The diffusion of the implanted radium and lead in the gallium arsenide (GaAs) semiconductor wafers was investigated through the alpha-particle energy degradation method. The alpha-particle spectra were determined using a standard silicon detector, support electronics and analysis software. It was revealed that in the GaAs wafers, the group IV elements such as tin and lead diffused through vacancies of either arsenic or gallium sites and that there was no shift in the average energy and activity of radium.

A study was conducted to characterize time-resolved differential reflections in InAs(sub x)P(sub 1-x)/InP strained-multiple-quantum wells. The evolution of the differential reflection dynamics was analyzed based on changes in the refractive index and cap absorption. Results indicated that carrier diffusion in the cap layer and barriers support a critical role in differential reflection dynamics.

The Fernelius extension to the Rosencwaig–Gersho theory for photothermal deflection spectroscopy (PDS) is modified to take into account multiple reflections and light trapping within a thin film-on-substrate system where both the thin film and the substrate can be absorbing. The extended model is used to simulate the PDS signal from bulk GaAs and GaNAs epilayers grown on GaAs substrates. While the PDS magnitude signal shows a strong dependence on the light trapping effects, the phase signal remains almost insensitive to this effect. However, the PDS relative phase is very sensitive to the sample thickness. [ABSTRACT FROM AUTHOR]

Presents information on a study which measured the optical absorption spectra of quantum well structures grown on InP(001 by organometallic vapor phase epitaxy. Experimental procedure; Results and discussion of the study.

Provides information on an experimental study observing time-resolved differential reflection in InAsxP1-x/InP (x...0.35) strained-multiple-quantum wells using the pump-probe technique. Methodology used to conduct the experiment; Results of the experiment; Information on the model calculations; Discussion on the results.