PV tandem cell

Multi-junction PV Tandem Cells for Hydrogen Production 501... 

PEC Setups with Multijunction and Multiple PV Cells 7.6.1 PEC Setup with Tandem Cells... 

PV current-voltage and power-voltage characteristics of a standard GaInP2/GaAs tandem cell were measured under 100 mW/cm2 illumination. The PV parameters under illumination were an open-circuit voltage Vroc = 2.32 V, a short-circuit current density Jsc = 13.4 mA/cm2, a fill factor FF = 0.88, and a PV conversion efficiency of 28.5%. Under the... 

Stack of bandgaps perfectly matched to the solar spectrum, the ultimate conversion efficiency at 1 Sun intensity increases to about 66%. For practical purposes, the stacks have been limited to two or three p-n junctions actual efficiencies of about 32% have been reported in laboratory-scale photovoltaic cells with two cascaded p-n junctions, and a world-record 40.7% efficiency has recently been reported with three bandgaps, but with a solar concentration factor of 240 (press release, Spectrolab Inc., 6 Dec. 2006). Although the tandem cell efficiencies are very impressive, their cost is very high, and their main present use is for space applications. However, terrestrial applications using solar concentrators to reduce the net costs are being developed and may lead to competitive PV power costs (McConnell and Symko-Davies, 2006). 

In this chapter, we discuss important work on material processing, characterization, and device performance of mixed molecular HJ PV cells. In Section 12.2, we first describe properties of vacuum codeposited mixtures of copper phthalocyanine (CuPc) and Cgo followed by the performance of PV cells using CuPc Cgo mixed HJs as the active region. Section 12.3 presents work on planar-mixed HJs (PM-HJs) which combine the advantages of mixed HJs with those of planar HJs. Individual PM-HJ cells were then stacked vertically to form tandem cells to achieve the highest efficiencies, which will be discussed in Section 12.4. Conclusions are presented in Section 12.5. 

An alternative tandem device being developed for solar water splitting is the PV/PEC hybrid photoelectrode. In this approach, a PEC top cell is monolithically stacked with a solid-state single-junction PV back cell. Such a photoelectrode device is compatible with both the one- and two-electrode reactor configurations described in Sect. 7.2.4, and the reactor-level considerations described in that section apply. Figure 7.28 shows a device level schematic for a specific two-electrode implementation incorporating a hybrid photocathode and a separate counter electrode. Possible alternative variations include the use of a hybrid photoanode instead of the photocathode, and the integration of the counter and... 

Figure 3.96). Cell A was connected to cell B by using a Cu sheet. The IPCE spectra of the individual and tandem cells are shown in Figure 3.97. The IPCE spectrum for the tandem DSSC contained peaks corresponding to the absorption spectra of both the dyes. Also shown in Figure 3.98 are the PV properties of single and tandem cells. The Voc of the tandem cell (1.13 V) was the sum of the Voc values of cell A (0.57 V) and cell B (0.57 V). 

A photovoltaic (PV) solar power system is a complete electrical source that uses solar cells to directly convert light energy into electricity. The system can be self-contained and completely autonomous or it can work in tandem with other conventional fuel-based sources of power to offer robust power availabihty. 

Multiple Bandgap Tandem Thin-film PV Cells for Hz Production... 

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