A Step‐by‐Step Optimization of the c‐Si Bottom Cell in Monolithic Perovskite/c‐Si Tandem Devices

Abstract

Perovskite/crystalline-silicon (c-Si) tandem devices are of great interest as potential candidates for next-generation photovoltaic devices. Such devices could combine a higher efficiency than c-Si with an acceptably low-production cost to enable further reductions in PV system costs. To date, little attention has been paid to the optimization of the c-Si bottom cell in these devices. However, for the highest possible efficiency, such an optimization is necessary. Here, the authors use numerical modeling to rigorously analyze the impact of doping type, doping concentration, and device architecture on the efficiency of the c-Si bottom cell. We show that the use of low-resistivity p-type wafers can result in higher efficiencies than the currently favored ntype, moderate resistivity wafers, for both homo-and heterojunction bottom c-Si devices. Two new device structureslocalized emitter rear localized (LERL) and reversed tunneling oxide passivating contact (rTOPCon) are proposed in order to further simplify cell fabrication and improve the device efficiency. The authors show that these structures are capable of the same high efficiencies as heterojunction cells while offering substantially greater temperature tolerance for the deposition of the perovskite top cell. The implementation of such optimized c-Si bottom cells will be crucial to the achievement of over 30% efficient tandem devices.

Perovskite Tandem Solar Cells: From Fundamentals to Commercial Deployment

“…To enhance the carrier mobility while still maintaining high conductivity of ITO, Sn in ITOs has been replaced by Zr and Zn. ,− For instance, the 100 nm sputtered Zr-doped In 2 O 3 with high band gap (>3.5 eV), high electron mobility (up to 77 cm 2 V –1 s –1 ), high conductivity (41 Ω s q –1 ), and high NIR transmittance is applied as the TCE in the semi-transparent MAPbI 3 PSC free of protective layer . The high electron mobility may be due to the reduction of the effective concentration of scattering centers .…”

Light Absorption and Recycling in Hybrid Metal Halide Perovskite Photovoltaic Devices

“…Both silicon‐perovskite and all‐perovskite multijunction devices require intricate device architectures, where each layer needs special considerations to ensure that the device achieves maximum efficiency . The current‐voltage characteristics of individual sub‐cells, light management throughout the device, and the chemical stability of the individual materials are the most important considerations when fabricating multijunction tandem PV devices .…”

“…[20] Both silicon-perovskite and all-perovskite multijunction devices require intricate device architectures, where each layer needs special considerations to ensure that the device achieves maximum efficiency. [21][22][23][24][25][26][27][28][29][30] The current-voltage characteristics of individual sub-cells, light management throughout the device, and the chemical stability of the individual materials are the most important considerations when fabricating multijunction tandem PV devices. [9,[28][29][30][31] In a two-terminal device configuration, the current (I) of the two subcells must match to ensure that there is a balance of electron and holes in the recombination layer.…”

Monolithic Perovskite-Carrier Selective Contact Silicon Tandem Solar Cells Using Molybdenum Oxide as a Hole Selective Layer

“…Hence, several research groups are involved in the development of perovskite-silicon tandem solar cells with enhanced optical absorption in the short wavelength band [5]; a group of Young Investigator Group Perovskite Tandem Solar Cells at the Helmholtz-Zentrum Berlin reports a high efficiency of 29.15% for perovskite-silicon solar cells [6]. Various silicon bottom cell concepts are being evaluated to further improve the conversion efficiency of perovskite-silicon tandem solar cells [7]. In this study, tandem cells are fabricated using carrier selective contact silicon solar cells as bottom structures.…”