Efficient and stable perovskite-silicon tandem solar cells through contact displacement by MgF _x

Abstract

The performance of perovskite solar cells with inverted polarity ( p-i-n ) is still limited by recombination at their electron extraction interface, which also lowers the power conversion efficiency (PCE) of p-i-n perovskite-silicon tandem solar cells. A ~1 nm thick MgF x interlayer at the perovskite/C 60 interface through thermal evaporation favorably adjusts the surface energy of the perovskite layer, facilitating efficient electron extraction, and displaces C 60 from the perovskite surface to mitigate nonradiative recombination. These effects enable a champion V oc of 1.92 volts, an improved fill factor of 80.7%, and an independently certified stabilized PCE of 29.3% for a ~1 cm 2 monolithic perovskite-silicon tandem solar cell. The tandem retained ~95% of its initial performance following damp-heat testing (85 Celsius at 85% relative humidity) for > 1000 hours.

Monolithic Perovskite–Perovskite–Silicon Triple-Junction Tandem Solar Cell with an Efficiency of over 20%

“…The effect of surface texturing can also be investigated as part of future work. While LiF, C 60, ALD SnO 2 , sputtered NiO x , and solution-processed SAM can be released on textured surfaces, the effect of the texture feature size will need to be investigated, especially on thin Au, which has yet to be demonstrated on a textured surface. For the interfacing between the subcells, a 20 nm indium tin oxide (ITO) layer is used for the silicon and mid-gap–perovskite junctions while ultrathin gold is used for the mid-gap– and high-gap–perovskite junctions.…”

“…14 For the electron-selective layer, the SnO 2 /C 60 stack is used for both middle-and high-band-gap cells in conjunction with a 1 nm thick LiF layer. In future work, alternatives to LiF 15 and C 60 16 that improve perovskite cell durability will be considered while retaining high performance. In addition, stoichiometrically engineered NiO x by sputtering will be investigated to further improve cell stability.…”

A Roadmap for Efficient and Stable All-Perovskite Tandem Solar Cells from a Chemistry Perspective

“…The perovskite/silicon tandem devices with MgF x demonstrated a certified 29.4% efficiency and much-improved stability. 74 Nejand and coworkers introduced indene-C60-propionic acid hexyl ester (IPH), a fullerene derivative, into the Pb−Sn perovskite/C 60 interface, which delivered a spike-like structure in energy-level alignment and consequently suppressed nonradiative recombination (Figure 4i). 76 Major work needs to be done in modifying ETLs to allow efficient carrier extraction and reduced nonradiative recombination at the perovskite/ETL interface.…”

“…(h) Energy level diagram of NBG perovskite and different fullerene derivatives. Panels (a) and (g) reproduced with permission from refs and , respectively. Copyright 2016 and 2022 American Association for the Advancement of Science, respectively.…”

“…Liu and co-workers inserted an ultrathin fluoride interlayer, especially MgF x , between the perovskite and C 60 interface to effectively mitigate C 60 -induced electronic disorders (Figure h). The perovskite/silicon tandem devices with MgF x demonstrated a certified 29.4% efficiency and much-improved stability . Nejand and co-workers introduced indene-C60-propionic acid hexyl ester (IPH), a fullerene derivative, into the Pb–Sn perovskite/C 60 interface, which delivered a spike-like structure in energy-level alignment and consequently suppressed nonradiative recombination (Figure i) .…”