Perovskite/silicon tandem solar cells are attractive for their potential for boosting cell efficiency beyond the crystalline silicon (Si) single‐junction limit. However, the relatively large optical refractive index of Si, in comparison to that of transparent conducting oxides and perovskite absorber layers, results in significant reflection losses at the internal junction between the cells in monolithic (two‐terminal) devices. Therefore, light management is crucial to improve photocurrent absorption in the Si bottom cell. Here it is shown that the infrared reflection losses in tandem cells processed on a flat silicon substrate can be significantly reduced by using an optical interlayer consisting of nanocrystalline silicon oxide. It is demonstrated that 110 nm thick interlayers with a refractive index of 2.6 (at 800 nm) result in 1.4 mA cm−² current gain in the silicon bottom cell. Under AM1.5G irradiation, the champion 1 cm2 perovskite/silicon monolithic tandem cell exhibits a top cell + bottom cell total current density of 38.7 mA cm−2 and a certified stabilized power conversion efficiency of 25.2%.

Textured perovskite/silicon tandem photovoltaic modules are compared to state-of-the-art silicon single-junction photovoltaic modules by annual energy yield modelling.

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25% annual PV growth is possible over the next decade

To sustain the silicon CMOS scaling beyond 100nm, an alternate gate dielectric with K > 7 is needed. The deposited high K dielectrics (metal oxides) have nonstoichiometeric composition and therefore have large electrical defects (traps) in the bulk of the dielectric and at the dielectric/semiconductor interface. In this paper, we report a novel doping method to quench traps in thin films of A1203 (K > 8). By adding small amounts of dopants such as Zirconium (Zr) or Silicon (Si), we have achieved -1 Onm thick aluminum oxide films with record low leakage current (< 10 -13A/mm2) and ultra-thin (3-5nm) aluminum oxide films with very low interface state density (-10 "/cm2-eV) at the silicordaluminum oxide interface. We propose a physics based model for the doping effect and selection of dopants for metal oxides with K > 10.

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Meeting the ambitious challenge of net-zero greenhouse gas emissions by 2050 and holding the average increase in global temperature below 1.5 °C necessitate the upscaling of readily available renewable energy sources, especially solar photovoltaics. Since the window of time to achieve this goal is closing fast, it is of paramount importance that we accelerate the decarbonization of the global energy system by increasing the power output of solar cells through advancing their power conversion efficiencies toward and beyond the Shockley–Queisser limit. In this Perspective, we describe how the integration of perovskites into the well-established silicon production infrastructure to form perovskite/silicon tandem photovoltaics can raise the rate of solar deployment. We present a holistic analysis of the technology from different perspectives, such as materials science, manufacturing, sustainability, and business, which highlights how the pairing of perovskite and silicon is advantageous at many different levels of consideration. Altogether, perovskite/silicon tandems deliver a technological disruption in efficiency while maintaining compatibility with the present photovoltaics industry, making it the fastest route to enhance the silicon market and rapidly address climate change.