Spectral Impact on Multijunction Solar Cells Obtained by Means of Component Cells of a Different Technology

Abstract

Spectral indices can be defined to characterize how the solar spectrum affects photovoltaic devices. The use of such indices is particularly important in technologies which are highly dependent on spectral variations, such as tandem, or multi-junction (MJ), solar cells. In this paper, we analyze the capability of three effective irradiance values, given by the photocurrents of the components of triple-junction solar cells, and covering different spectral bands, to define the spectrum condition. Even though these parameters will be based on a particular type of MJ solar cell, they provide enough information to accurately assess the spectral impact on other types of MJ solar cell technologies with significantly different spectral responses. Consequently, specific component cells for each MJ solar cell technology may not be necessary needed and a reference technology could be used for all them, providing a way for the future standardization of these devices as a mean of defining the solar spectral condition.

Increasing the Resolution and Spectral Range of Measured Direct Irradiance Spectra for PV Applications

“…In parallel, experimental determinations of SF are difficult in practice because the wavelength range (e.g., 350 nm to 1050 nm, or at best 300 nm to 1100 nm) of the most common spectroradiometers in current use is shorter than the spectral response of some PV technologies (such as polycrystalline silicon, copper indium diselenide, lattice-matched germanium-based, or multijunction cells used in concentrating PV applications), which can be sensitive up to ≈2 µm [16,17]. Figure 1 shows the relative spectral response of seven PV technologies (as described in [5]) with wavelengths ranging from 300 nm to 1350 nm along with a common solar direct irradiance spectrum (G bλ ) measured in this work with a commercial spectroradiometer.…”

From component to multi-junction solar cells for spectral monitoring

“…The use of spectrally-matched sensors is also useful for determining the internal current ratios of a solar cell under concentration; and determining the sub-cell limitation of the device current under a particular spectral condition [9]. Nevertheless, the CPV community tries to demonstrate that a set of isotypes of a particular technology can be used to predict the prevailing conditions for other technologies [10][11]. This approach will be limited by the outdoor power rating and the characterization possibilities.…”