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The origins of parasitic heating for photovoltaic (PV) technologies based on silicon, perovskites, and their combination in monolithic tandems are investigated. To quantify heating losses, the cooling score (CS) as a new simple metric, representing the percentage of incident solar irradiance not contributing to module heating is introduced. This is a function of both the optical structure and power conversion efficiency (PCE) of the PV modules and allows a fair comparison between different technologies under identical performance‐evaluation scenarios. Silicon single‐junction devices have the lowest CS due to their low bandgap (causing significant carrier thermalization losses) and their use of light‐trapping structures to increase their PCE which also undesirably increases parasitic absorption of sub‐bandgap photons. Conversely, perovskite single‐junction devices show the highest CS in all studied performance‐evaluation scenarios thanks to their wider bandgap and high absorption coefficient, enabling absorption of all solar photons that may contribute to the photocurrent without requiring light‐trapping structures. While perovskite/silicon tandems minimize thermalization losses, they also usually employ light‐trapping structures in their bottom cell to increase their PCE, which lowers their CS. Through simulation and outdoor experiments, it is demonstrated that an efficient module‐cooling environment may significantly suppress the detrimental effects associated with a low CS. [ABSTRACT FROM AUTHOR]

Sputtered nickel oxide (NiOx) is an attractive hole‐transport layer for efficient, stable, and large‐area p‐i‐n metal‐halide perovskite solar cells (PSCs). However, surface traps and undesirable chemical reactions at the NiOx/perovskite interface are limiting the performance of NiOx‐based PSCs. To address these issues simultaneously, an efficient NiOx/perovskite interface passivation strategy by using an organometallic dye molecule (N719) is reported. This molecule concurrently passivates NiOx and perovskite surface traps, and facilitates charge transport. Consequently, the power conversion efficiency (PCE) of single‐junction p‐i‐n PSCs increases from 17.3% to 20.4% (the highest reported value for sputtered‐NiOx based PSCs). Notably, the N719 molecule self‐anchors and conformally covers NiOx films deposited on complex surfaces. This enables highly efficient textured monolithic p‐i‐n perovskite/silicon tandem solar cells, reaching PCEs up to 26.2% (23.5% without dye passivation) with a high processing yield. The N719 layer also forms a barrier that prevents undesirable chemical reactions at the NiOx/perovskite interface, significantly improving device stability. These findings provide critical insights for improved passivation of the NiOx/perovskite interface, and the fabrication of highly efficient, robust, and large‐area perovskite‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Perovskite single-junction devices show highest CS, followed by perovskite/silicon tandems. Cooling score, parasitic heating, perovskites, silicon, tandem Keywords: cooling score; parasitic heating; perovskites; silicon; tandem EN cooling score parasitic heating perovskites silicon tandem 1 1 1 06/27/23 20230623 NES 230623 B Cooling Score b In article number 2300013, Lujia Xu, Stefaan De Wolf, and co-workers introduce the cooling score (CS) to quantify parasitic heating for photovoltaic technologies. [Extracted from the article]

Nickel oxide, passivation, perovskites, solar cells, tandems Linked Nickel Oxide/Perovskite Interface Passivation for High-Performance Textured Monolithic Tandem Solar Cells (Adv. Keywords: nickel oxide; passivation; perovskites; solar cells; tandems EN nickel oxide passivation perovskites solar cells tandems 1 1 1 10/29/21 20211027 NES 211027 B Interface Passivation b In article number 2101662, Furkan H. Isikgor, Stefaan De Wolf and co-authors develop a NiO SB I x i sb /perovskite interface passivation strategy using an organometallic dye (N719) molecule. [Extracted from the article]

An innovative sequential eco‐friendly spray coating (SEF‐SC) technique is developed to uniformly deposit metal halide perovskite films on macroscale textured surfaces, such as textured crystalline‐silicon wafers. Contrasting with previous work on spray‐coated perovskite solar cells, the method presented in this work completely avoids the use of toxic and dangerous solvents. Both MAPbI3 and CsFAMAPbI3−xBrx perovskite films deposited by SEF‐SC show excellent optoelectronic properties and no phase segregation, even when synthesized in ambient conditions. Uniform perovskite coatings are obtained on textured‐silicon heterojunction solar cells underlining the promise of this method, which holds the potential for scalable wet processing of perovskites on rough substrates, such as for low‐cost perovskite/silicon tandem solar cell fabrication. [ABSTRACT FROM AUTHOR]