Design of a GaInP/GaAs tandem solar cell for maximum daily, monthly, and yearly energy output

Abstract

Abstract. Solar concentrator cells are typically designed for maximum efficiency under the AM1.5d standard spectrum. While this methodology does allow for a direct comparison of cells produced by various laboratories, it does not guarantee maximum daily, monthly, or yearly energy production, as the relative distribution of spectral energy changes throughout the day and year. It has been suggested that achieving this goal requires designing under a nonstandard spectrum. In this work, a GaInP/GaAs tandem solar cell is designed for maximum energy production by optimizing for a set of geographically-dependent solar spectra using detailed numerical models. The optimization procedure focuses on finding the best combination of GaInP bandgap and GaInP and GaAs sub-cell absorber layer thicknesses. It is shown that optimizing for the AM1.5d standard spectrum produces nearly maximum yearly energy. This result simplifies the design of a dual-junction device considerably, is independent of the optical concentration up to at least 500 suns, and holds for a wide range of geographic locations. The simulation results are compared to those obtained using a more traditional, ideal-diode model.

Inverted Metamorphic III–V Triple-Junction Solar Cell with a 1 eV CuInSe2Bottom Subcell

“…The absorption range of the top subcell is limited by the bandgap close to 650 nm ( = 1.9 eV). The high response in the UV is due primarily to surface recombination at the top interfaces of the GaInP subcell (∼10 6 cm/s), in agreement with Haas et al [29]. Dopingdependent SRH minority carrier lifetime parameters can provide further calibration of the top subcell EQE in terms of agreement with experiment.…”

GaInP/GaAs three-terminal heterojunction bipolar transistor solar cell

“…21 The latter results from a higher tolerance of 3T and 4T architectures against non-optimal E G values, which facilitates the consideration of economic criteria in the design of MJSC devices. But the positive effect that these factors may have in the nal price of electricity can be jeopardized by an increase in fabrication costs, since most 3T and 4T practical devices reported still involve a structural complexity comparable to current-matched 2T devices 8,[22][23][24][25] (see Figures 1a and b) to which it is added the extra technological complexity introduced by the additional terminals. The HBTSC concept demonstrated here is material-agnostic and its structural simplicity opens the path to new, low-cost fabrication strategies that can compensate the cost of intricate device processing.…”

Energy-yield prediction for II–VI-based thin-film tandem solar cells

“…1,2 We introduce a simple, but powerful, framework to predict tandem energy-yield, consisting of a semi-empirical efficiency model coupled to easily accessible clear-sky solar spectra and ambient temperature. This model has simplicity and speed advantages over previous models, based on numerical device physics simulators, [3][4][5] without sacrificing accuracy. Our approach also stands in contrast with previous semi-empirical models, which require the tandem solar cells to be developed and fully characterized before energy-yield prediction can be made.…”