Solar Cell Characterizations

The performance of a photovoltaic cell is characterized by the power conversion efficiency r]p, which is defined by  

FIGURE 3. A typical current-voltage characteristic for a photovoltaic cell. 

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Dloczik L., Ileperuma O., Lauermann I., Peter L. M., Ponomarev E. A., Redmond G., Shaw N. J. and Uhlendorf I. (1997), Dynamic response of dye-sensitized nanocrystalline solar cells characterization by intensity-modulated photocurrent spectroscopy , J. Phys. Chem. B 101, 10281-10289. 

Global AMI.5 sun illumination of intensity 100 mW/cm ). The DOS (or defect) is found to be low with a dangling bond (DB) density, as measured by electron spin resonance (esr) of - 10 cm . The inherent disorder possessed by these materials manifests itself as band tails which emanate from the conduction and valence bands and are characterized by exponential tails with an energy of 25 and 45 meV, respectively the broader tail from the valence band provides for dispersive transport (shallow defect controlled) for holes with alow drift mobiUty of 10 cm /(s-V), whereas electrons exhibit nondispersive transport behavior with a higher mobiUty of - 1 cm /(s-V). Hence the material exhibits poor minority (hole) carrier transport with a diffusion length <0.5 //m, which puts a design limitation on electronic devices such as solar cells. 

Multilayered structures play an important role in the production of, e.g., biomaterials, catalysts, corrosion protectors, detectors/diodes, gas and humidity sensors, integral circuits, optical parts, solar cells, and wear protection materials. One of the most sophisticated developments is a head-up-display (HUD) for cars, consisting of a polycarbonate substrate and a series of the layers Cr (25 nm), A1 (150 nm), SiO, (55 nm), TiO, (31 nm), and SiO, (8 nm). Such systems should be characterized by non-destructive analytical methods. 

The chemical and electronic properties of elements at the interfaces between very thin films and bulk substrates are important in several technological areas, particularly microelectronics, sensors, catalysis, metal protection, and solar cells. To study conditions at an interface, depth profiling by ion bombardment is inadvisable, because both composition and chemical state can be altered by interaction with energetic positive ions. The normal procedure is, therefore, to start with a clean or other well-characterized substrate and deposit the thin film on to it slowly at a chosen temperature while XPS is used to monitor the composition and chemical state by recording selected characteristic spectra. The procedure continues until no further spectral changes occur, as a function of film thickness, of time elapsed since deposition, or of changes in substrate temperature. 

TVivedi, R. Somboonsuk, K., in Proc. Flat-Plate Solar Array Research Forum on the High Speed Growth and Characterization of Crystals for Solar Cells K. Dumas EM., JPL-Publication 84-23, 1984. 

Electrolyte contacts have been used to characterize as-deposited and annealed CdS/CdTe solar cell structures by photocurrent spectroscopy and electrolyte elec-troabsorbance/electroreflectance measurements (EEA/EER) [267-269]. 

Kampmann A, Cowache P, MokiU B, Lincot D, Vedel J (1995) Characterization of (111) cadmium telluiide electrodeposited on cadmium sulphide. J Cryst Growth 146 256-261 Britt J, Ferekides C (1993) Thin-film CdS/CdTe solar cell with 15.8% efficiency. Appl Phys Lett 62 2851-2852... 

Heller A, Chang KC, Miller B (1977) Spectral response and efficiency relations in semiconductor liquid junction solar cells. J Electrochem Soc 124 697-700 Elhs AB, Kaiser SW, Wrighton MS (1976) Optical to electrical energy conversion. Characterization of cadmium sulfide and cadmium selenide based photoelectrochemical cells. J Am Chem Soc 98 6855-6866... 

Hodes G, Manassen J, Neagu S, Cahen D, Mirovski Y (1982) Electroplated cadmium chalcogenide layers Characterization and use in photoelectrochemical solar cells. Thin Solid Films 90 433-438... 

Kesmez, O., Erdem Camurlu, H., Burunkaya, E. and Arpac, E. (2009) Sol-gel preparation and characterization of anti-reflective and self-cleaning Si02-Ti02 double-layer nanometric films. Solar Energy Materials and Solar Cells, 93, 1833-1839. 

Wada, T. Nishitani, M. Negami, T. Kohara, N. Ikeda, M. Terauchi, M. 1994. Microstructural characterization of substrate-type and superstrate-type CuInSe2 thin film solar cells. Proc. 12th European Photovoltaic Solar Energy Conf. pp. 1542-1545. 

Abou-Elfotouh, F. A. Moutinho, FI. Bakry, A. Coutts, T. J. Kazmerski, L. L. 1991. Characterization of the defect levels in copper indium diselenide. Solar Cells 30 151-160. 

Kuranouchi, S. Konagai, M. 1995. Characterization of ZnO/CdS/CuInSe2 thin-film solar cells by deep-level transient spectroscopy. Jpn. J. Appl. Phys. 34 2350-2351. 

Ozer, N. 2001. Optical properties and electrochromic characterization of sol-gel deposited ceria films. Solar Energy Mater. Solar Cells 68 391-400. 

Sankapal, B. R. Ennaoui, A. Guminskaya, T. Dittrich, Th. Bohne, W. Rohrich, J. Strub, E. Lux-Steiner, M. Ch. 2005. Characterization of p-Cul prepared by the SILAR technique on Cu-tape/n-CuInS2 for solar cells. Thin Solid Films 480-481 142-146. 

Menzies, D. B. Dai, Q. Bourgeois, L. Caruso, R. A. Cheng, Y. B. Simon, G. P. Spiccia, L. 2007. Modification of mesoporous Ti02 electrodes by surface treatment with titanium(IV), indium(III) and zirconium(IV) oxide precursors Preparation, characterization and photovoltaic performance in dye-sensitized nanocrystalline solar cells. Nanotechnology 18 125608. 

The wafers are processed into solar cells, the majority of which have a diode structure, as sketched in Figure 11.4, characterized by a thin, diffused, doped emitter, screen-printed front and back contacts and a front-surface antireflective coating. Prior to the effective cell manufacturing step, a chemical treatment of the silicon wafers removes... 

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