Large area solar cells

It was mentioned earlier (Section 3.4) that all materials can be rendered amorphous. What is often not recognized by chemists is that a large variety of materials - catalysts, catalyst supports, xerographic photoreceptors, optical fibres, large-area solar cells and many biominerals - are noncrystalline (Elliott et al, 1986). Noncrystalline solids possess no long-range order and their structure is akin to that of a frozen liquid. Most... 

Record efficiencies of 18.2% for EFG and 17.9% for SR were obtained using lab-type processing including double layer ARC (DARC) [85,88]. Large area solar cells processed according to an industrial-type fabrication scheme show significantly lower efficiencies. Record values of 15.7% for EFG (10 x 10 cm2... 

The most extensively studied a-Si H solar cells, due to their highest conversion efficiencies, are those fabricated in the form of p-i-n devices. Typically, the p-a-Si H film is less than 10 nm, the undoped (-a-Si H is between 200 and 700 nm and w-a-Si H layer is approx. 30-50 nm. The layers are deposited on each other in successive plasma reactor chambers connected by vacuum locks. A metaUic electrode is used as a substrate. An opposite optically transparent and electrically conducting electrode (e.g. ITO film) is deposited from the top. Today, the commercial large-area solar cell modules based on a-Si H are fabricated with a stabilized conversion efficiency (the ratio of the maximum power output to the solar energy input) in the 4-6 % range (Green, 2007). 

Small-area thin-film CdTe solar cells have been fabricated with sunlight-to-electricity conversion efficiencies near 16%, comparable to crystalline siUcon solar cells in large-scale manufacturing. Large-area monolithic integrated CdTe modules have been fabricated with efficiencies of ca 10%, comparable to crystalline siUcon modules commercially available. 

The chapter is organized as follows the second section will discuss the photophysics of conjugated polymer/fullerene composites as a standard model for a charge-generating layer in plastic solar cells. Pristine polymer devices will be discussed in the third section while bilayer and interpenetrating network devices are presented in Sections 4 and 5. Section 6 contains some remarks on large area plastic solar cells and Section 7 conclusions. 

Figure 15-31. l/V characteristics of a large area plastic solar cell ( illuminated with 488 nm, 10 rnW/ cm2). FF for the 1TO plastic cell is 0.35. As reference a pholocurrcnl of a polycrystalline Si cell is plotted ( ), 10 limes reduced. 

Flexible, Large Area, Plastic Solar Cells 551... 

How can such problems be counterbalanced Since a large capacitance of a semiconductor/electrolyte junction will not negatively affect the PMC transient measurement, a large area electrode (nanostructured materials) should be selected to decrease the effective excess charge carrier concentration (excess carriers per surface area) in the interface. PMC transient measurements have been performed at a sensitized nanostructured Ti02 liquidjunction solar cell.40 With a 10-ns laser pulse excitation, only the slow decay processes can be studied. The very fast rise time cannot be resolved, but this should be the aim of picosecond studies. Such experiments are being prepared in our laboratory, but using nanostructured... 

The research effort in many laboratories around the world on the optimization of laboratory-scale (1-cm- area) cells has led to the development of large-area (1 m ) solar cell modules with an efficiency exceeding 10% [613,614]. In a module individual cells can be connected in series or parallel, depending on the desired... 

Dhere, N.G., Kadam, A.A., Kulkarni, S.S., Bet, S.M., and Jahagirdar, A.H., Large area CIGS2 thin film solar cells on foils Nucleus of a pilot plant, Solar Energ.., 77, 697, 2004. 

Gangopadhyay et al.48 used a CBD ZnS antireflection coating on large-area commercial monocrystalline silicon solar cells, resulting in a 13.8% efficiency. Ennaoui et al.49 deposited CBD Zn(Se,OH)x films on Cu(In,Ga)(S,Se)2. They reported an active-area efficiency of up to 15.7% and a total-area efficiency of up to 13.26% for such devices. 

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