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We conducted a chronoamperometric study to observe the electrochemical behaviors of the nucleation mechanism of electrodeposited Cu(In,Al)Se 2 films. A change from instantaneous nucleation to progressive nucleation was observed by increasing the copper concentration. SEM and EDS analyses demonstrated that the surface morphologies and chemical compositions of precursor and post-annealed Cu(In,Al)Se 2 films were influenced by the nucleation mechanism. They exhibited that Cu(In,Al)Se 2 films had roughly cauliflower-like and triangular structures with Cu-poor composition at the instantaneous nucleation mechanism, whereas smooth and round structures with Cu-rich composition at the progressive nucleation mechanism. Additionally, the quality, growth orientation, composition phase, and optical energy band gap of Cu(In,Al)Se 2 films were examined using X-ray diffraction (XRD) patterns, Raman spectra, and ( αhν ) 2 vs. hν plots (UV–vis). Thereafter, the performances of rudimentary Cu(In,Al)Se 2 solar cells fabricated at various copper concentrations were discussed, the conversion efficiency of electrodeposited Cu(In,Al)Se 2 solar cells were unpublished in previous literatures. Our studies demonstrated that the performances of Cu(In,Al)Se 2 solar cells were significantly related to the surface morphology and composition of Cu(In,Al)Se 2 absorber layer. The highest conversion efficiency of Cu(In,Al)Se 2 solar cells fabricated at a 2-mM copper concentration was 1.96% with open-circuit voltage, short-circuit current, fill factor, R sh and R s values of 0.189 V, 29.21 mA/cm 2 , 35.4%, 125 Ω and 2.82 Ω, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The study addresses the optical properties and morphologies of Al-doped ZnO (AZO) films textured by the chemical wet-etching method using three different acid solutions: HCl, HNO3, and H3PO4. An initial AZO film was sputtered on a glass substrate by rf magnetron sputtering. The film surface was then textured by wet-etching using diluted HCl, HNO3, or H3PO4. The average transmittance of all the post-treated ZnO:Al films remains around 75–80% as measured by a UV–vis analyzer. A haze ratio calculation shows that the light scattering properties can be significantly controlled by varying the etchant species, acid concentration, and etching time. Further, the HNO3 etchant gives the highest haze ratio of 43.0% at a wavelength of 550nm. Compared with solar cells deposited on non-textured ZnO:Al films, a significant enhancement in the short-circuit current density of 17.8% for the a-Si solar cells with textured ZnO:Al films was achieved. [Copyright &y& Elsevier]

In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H 3 PO 4 , HCl, and HNO 3 are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO 3 exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10 −4 Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H 3 PO 4 , HCl and HNO 3 were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO 3 -etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm 2 and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film. [ABSTRACT FROM AUTHOR]