In situ recombination junction between p-Si and TiO ₂ enables high-efficiency monolithic perovskite/Si tandem cells

Abstract

A minimalist approach to integration yields tandem solar cells with high efficiency.

Monolithic Perovskite/Si Tandem Solar Cells: Pathways to Over 30% Efficiency

“…We implement experimentally derived electrical input parameters and the generation profile derived from the above optical simulation into the Quokka cell simulator to assess the performance of the Si cell under sunlight filtered by the top‐cell (Figure S3, Supporting Information). Since it is challenging to separately characterize the subcells in a 2‐T tandem configuration due to the difficultly in device isolation, parameters including saturation current density ( J 0 ) at both surfaces, the bulk lifetime, and the front contact resistance were measured on co‐processed or similarly processed test structures rather than complete tandem cells . The current density extracted from the modeled J–V curves (Figure S3, Supporting Information) agrees well with those measured for our tandem devices.…”

“…The significant combined optical loss of 7.8 mA cm −2 highlights the utmost importance of designing advanced architectures for better light management to unleash the full potential of the monolithic tandems. We note that the simulations predict an absorbed photocurrent in the active layers that exceeds the values measured in our device . This discrepancy can be attributed foremost to the absence of shading losses to a front metal grid, which were ≈3% of the active area of the device.…”

“…Applied in tandems, this would allow fabrication of high‐efficiency PSCs based on mesoporous‐structured TiO 2 which required annealing at over 400 °C. Poly‐Si/SiO x passivating contact Si technology was recently demonstrated for the first time in the interlayer‐free perovskite/Si tandem solar cell with efficiencies over 24% . With doping densities in the poly‐Si layer that are typically very high, it is likely that such technology will also be compatible with other interlayer materials including tunneling layers or transparent conductive oxide (TCO) layers.…”

“…Our tandem is built‐up by placing a mesoporous n‐i‐p perovskite cell directly on a Si bottom cell based on a SiN x ‐passivated textured rear side and polished front side, using either a boron‐diffused emitter or a poly‐Si/SiO x ‐passivated heterojunction . A textured morphology of the rear‐side of the tandem is utilized due to its proven capability to improve near‐infrared (NIR) light scattering without impacting the solution deposition for the top perovskite.…”

Highly efficient monolithic perovskite silicon tandem solar cells: analyzing the influence of current mismatch on device performance

“…4,5,7,19,20 Recently, the p-i-n architecture for perovskite top-cells prevailed over the n-i-p architecture, especially due to temperature limitations of the SHJ cell (200 C), which prevents the use of high temperature process, such as sintering of mesoporous TiO 2 . [21][22][23] Although there are possibilities to deposit the n-type contact at lower temperatures, 24 and use temperature stable bottom cells, 25,26 strong absorption of the p-type top contacts was reported for n-i-p architectures. 14,27 An efficient device design was presented by Bush et al, who mitigated these losses by utilizing a p-i-n top cell architecture with reduced parasitic absorption in the n-type top contact.…”