Matching of Silicon Thin-Film Tandem Solar Cells for Maximum Power Output

Abstract

We present a meaningful characterization method for tandem solar cells. The experimental method allows for optimizing the output power instead of the current. Furthermore, it enables the extraction of the approximate AM1.5g efficiency when working with noncalibrated spectra. Current matching of tandem solar cells under short-circuit condition maximizes the output current but is disadvantageous for the overall fill factor and as a consequence does not imply an optimization of the output power of the device. We apply the matching condition to the maximum power output; that is, a stack of solar cells is power matched if the power output of each subcell is maximal at equal subcell currents. The new measurement procedure uses additional light-emitting diodes as bias light in theJVcharacterization of tandem solar cells. Using a characterized reference tandem solar cell, such as a hydrogenated amorphous/microcrystalline silicon tandem, it is possible to extract the AM1.5g efficiency from tandems of the same technology also under noncalibrated spectra.

Analysis of the light-induced degradation of differently matched tandem solar cells with and without an intermediate reflector using the Power Matching Method

“…The current matching is most commonly realized to optimize efficiency. However, as has been shown before [2,3], the short-circuit current-matching does not lead to the optimum output power if the current/voltage (JV)-characteristics of the top and bottom cell differ. In this article, the aspect of an optimum matching will be discussed in the context of lightinduced degradation [4].…”

“…Therefore the same tandem solar cell can be characterized under matching conditions varied from top-to bottom-limitation. Further details on this method can be found in [3]. (1), this parameterization will be motivated and discussed at the end of this section).…”

Tandem Solar Cells Based on Cu2O and c-Si Subcells in Parallel Configuration: Numerical Simulation

“…A four-terminal device has the subcells electrically decoupled and independently controllable that can be connected in parallel, ensuring a maximum output power at all times [18]. The tandem efficiency is estimated to reach values above 30% [1,2,6,19]. A possible four-terminal configuration is presented in Figure 1 [20].…”

“…Recently, tandem solar cells made up of various materials such as silicon (monocrystalline, polycrystalline, and amorphous) [1][2][3], perovskite [4][5][6], polymer [7,8], dyesensitized solar cells [9], and quantum dot solar cells [10] have been theoretically or experimentally studied. However, tandems with a high efficiency at low cost have still not been realized.…”

Triple-junction amorphous/microcrystalline silicon solar cells: Towards industrially viable thin film solar technology

“…Furthermore, in order to fully characterize the maximum efficiency potential of the devices a LED-based modification of the Wacom sun simulator has been developed, recently described in [19][20][21]. This powerful characterization method is schematically presented in Fig.…”