NE: Monolithic all-perovskite tandem solar cells with 24.8% efficiency exploiting comproportionation to suppress Sn(ii) oxidation in precursor ink (2019) using metallic tin to reduce Sn4+ (the oxidation product of Sn2+) to Sn2+, and reduce Pb-Sn Sn vacancy defects in perovskites. Through this method, the charge carrier diffusion length of narrow band gap perovskite materials is improved, and the best material reaches 3 microns. A PCE of 21.1% was obtained in a 1.22 eV narrow bandgap solar cell. The PCE for small-area devices (0.049 square centimeters) of all-perovskite tandem cells is 24.8%, and the PCE for large-area devices (1.05 square centimeters) is 22.1%. These series-connected cells maintained 90% performance after operating at their maximum power point for 463 hours under full 1-sun illumination.
ACS energy letter: Solution-Processed Monolithic All-Perovskite Triple-Junction Solar Cells with Efficiency Exceeding 20% (2020) Solution-processed method for high-efficiency all-Perovskite triple-junction solar cells using optimal energy gap perovskite. By developing interconnect layers compatible with solution processing of perovskite absorbing materials, a monolithic all-perovskite triple-junction cell with an open circuit voltage of 2.8 V and a fill factor of 81.1% was obtained.
https://dx.doi.org/10.1021/acsenergylett.0c01184
NE: All-perovskite tandem solar cells with 24.2% certified efficiency and area over 1 cm2 using surface-anchoring zwitterionic antioxidant (2020) Use strong reduction of surface-anchored amphiphilic molecules while improving the efficiency of narrow energy gap sub-cells , uniformity and stability. This amphiphilic antioxidant inhibits the oxidation of Sn2+ and passivates defects on the grain boundary surface of the mixed lead-tin perovskite film, allowing the efficiency of single-junction solar cells to reach 21.7% (certified as 20.7%). Further, a certified efficiency of 24.2% was obtained in a 1 cm2 all-perovskite tandem cell. In the laboratory, power conversion efficiencies of 25.6% and 21.4% were obtained for 0.049 cm2 and 12 cm2 devices, respectively. The packaged tandem device maintained 88% of its initial performance after 500 hours of operation at room temperature, under sunlight, and at a device temperature of 54-60 degrees Celsius.
Science China chemistry: Cross-linked hole transport layers for high-efficiency perovskite tandem solar cells (2021) By replacing the commonly used PTAA hole transport layer with in-situ cross-linked small molecule N4, N4'-bis(naphthalene) -1-yl)-N4,N4'-bis(4-vinylphenyl)biphenyl-4,4'-diamine (VNPB), which improves the open circuit voltage (VOC) and Photoelectric conversion efficiency (PCE). At the VNPB/perovskite interface, stronger interactions and lower trap density improve the PCE and stability of wide-bandgap perovskite solar cells. By using cross-linked HTL in front-end wide-gap sub-cells, photoelectric conversion efficiencies of 24.9% and 25.4% were achieved in perovskite/perovskite and perovskite/silicon tandem solar cells, respectively.
Solar RRL: Thermally Stable All-Perovskite Tandem Solar Cells Fully Using Metal Oxide Charge Transport Layers and Tunnel Junction (2021) uses metal oxides (NiOx and SnO2) as the hole transport layer and electron transport layer. The metal matrix composite layer is replaced by a stable and conductive indium tin oxide nanocrystalline film to prepare an all-metal oxide tunnel junction. Based on these design strategies, the encapsulated all-perovskite tandem solar cell maintained an initial efficiency of 85% after 2,500 hours of stress at 85 degrees Celsius, and maintained the efficiency after 900 hours of operation at the maximum power point and operating temperature of about 65 degrees Celsius. 80%+ initial performance.
https://onlinelibrary.wiley.com/doi/abs/10.1002/solr.202100814
Nature: All-perovskite tandem solar cells with improved grain surface passivation (2022) For detailed analysis, please see the previous push: 26.7% all-perovskite stack-narrow band gap optimization
Science: Scalable processing for realizing 21.7%-efficient all-perovskite tandem solar modules (2022) For detailed analysis, please see the previous push: All-perovskite laminated modules, in one word: convinced!
AM: Steric Engineering Enables Efcient and Photostable WideBandgap Perovskites for All-Perovskite Tandem Solar Cells (2022) Wide bandgap can be obtained by alloying dimethylammonium and chloride into mixed cation mixed halide perovskites , while the bromide content is greatly reduced, while lattice strain and trap density are also minimized. The wide-bandgap perovskite solar cell showed significantly improved performance and photostability, maintaining over 90% of its initial efficiency after 1,000 hours of operation at the maximum power point. The triple-cation/trihalide ion wide-bandgap perovskite achieved through three-dimensional engineering further achieved a stable conversion efficiency of 26.0% in all-perovskite tandem solar cells.
https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202110356
NE: Flexible all-perovskite tandem solar cells approaching 25% efficiency with molecule-bridged hole-selective contact (2022) uses a mixture of two organic molecules based on carbazole core and phosphonic acid anchoring groups to form self-assembled monomers molecular layer, and connects the perovskite and low-temperature-processed NiO nanocrystal films. These organic molecules act as hole-selective materials that help mitigate interfacial recombination and promote hole extraction. Demonstrated a flexible all-perovskite tandem solar cell with an efficiency of 24.7% (certified 24.4%), outperforming all types of flexible thin-film solar cells. On a larger device area (1.05 cm2), an efficiency of 23.5% was also reported. The molecularly bridged interface allows the flexible all-perovskite tandem solar cell to maintain its initial performance after 10,000 bends in a bending environment with a radius of 15 mm.
https://www.nature.com/articles/s41560-022-01045-2
Joule: Performance optimization of monolithic allperovskite tandem solar cells under standard and real-world solar spectra (2022) Constructing monolithic allperovskite tandem solar cells is a promising strategy to improve efficiency beyond the single-junction limit. However, two fundamental questions remain unanswered:
Is "current matching" always necessary to maximize series efficiency?
How to minimize current mismatch losses under real solar spectrum?
The authors answer these questions by performing simulations using validated optical and electrical models. Under standard test conditions, the best efficiency of this all-perovskite tandem structure is when the short-circuit current density of the wide-bandgap top sub-cell is about 1.05 mA/cm², which is better than that of the bottom sub-cell. To answer the second question, we use actual weather data as input to a simplified model, significantly reducing computational time and improving annual energy output by up to 4.5%. Marginal current mismatch losses, or even gains, alleviate concerns about rated series products in the actual solar spectrum.
Elight: Revealing the output power potential of bifacial monolithic all-perovskite tandem solar cells (2022) For the first time, bifacial monolithic all-perovskite tandem solar cells were demonstrated and their output power potential was revealed. Double-sided series connection is achieved by replacing the single-sided series-connected rear metal electrode with a transparent conductive oxide electrode. Energy gap engineering is used to achieve current matching under different rear side lighting conditions. The bifacial series connection exhibits a high output power density of 28.51 mW cm^-2 under actual backside lighting conditions. Further energy output calculations show that under different climate conditions, double-sided series connection can achieve considerable energy output gains compared to single-sided series connection under different ground albedo.
https://elight.springeropen.com/articles/10.1186/s43593-022- 00028-w?via=indexdotco
NC: Oxidation-resistant all-perovskite tandem solar cells in substrate configuration (2023) Using a substrate configuration (first depositing the back sub-cell, then depositing the front sub-cell), the oxidizable narrow bandgap perovskite is deeply buried in the device layer stack, thereby achieving an all-perovskite tandem connection. By using a guanidinium tetrafluoroborate additive in a wide-bandgap perovskite subcell, an efficiency of 25.3% was achieved in a substrate-configured all-perovskite tandem cell. Unpackaged devices show no performance degradation after being stored in dry air for 1,000 hours. The substrate configuration also expands the choice of flexible substrates: 24.1% and 20.3% efficient flexible all-perovskite tandem solar cells were achieved on copper-coated polyethylene naphthalene and copper foil, respectively.
https://doi.org/10 .1038/s41467-023-37492-y
NE: Inorganic wide-bandgap perovskite subcells with dipole bridge for all-perovskite tandems (2023) For detailed analysis, please see previous push: Latest NE: All-perovskite stack based on all-inorganic perovskite
Nature: All-perovskite tandem solar cells with 3D/3D bilayer perovskite heterojunction (2023) For detailed analysis, please see previous posts: Nature: All-perovskite stack efficiency record 28%
Angew: Efficient All-Perovskite Tandem Solar Cells with Low-Optical-Loss Carbazolyl Interconnecting Layers (2023) uses metal oxide nanocrystal layers anchored by carbazole-based hole-selective molecules (CHs). These layers Exhibits lower optical losses for replacement of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as hole in lead-tin (Pb-Sn) perovskite subcells Transport layers (HTLs) and interconnect layers (ICLs) in all-perovskite tandem solar cells. An optically transparent layer of indium tin oxide nanocrystals (ITO NCs) is used to enhance the anchoring of CHs, while a mixture of two CHs is used to adjust the surface energy level of the ITO NCs. The optimized hybrid Pb-Sn narrow bandgap perovskite solar cell exhibits a high efficiency of 23.2% with a high short-circuit current density (Jsc) of 33.5 mAcm². In the all-perovskite tandem solar cell, a further high efficiency of 28.1% was achieved, which is the highest Jsc so far of 16.7 mAcm². The encapsulated tandem solar cells maintained 90% of the baseline performance after operating at the maximum power point (MPP) for 500 hours under full 1-sun illumination.
https://onlinelibrary.wiley.com/doi/epdf/10.1002/ange.202313374
AM: Scalable Solution-Processed Hybrid Electron Transport. Layers for Efficient All-Perovskite Tandem Solar Modules (2023) developed a blade-coated hybrid fullerene (HF) in all-Perovskite tandem solar modules Scalable solution processing method for coating on wide band gap (approximately 1.80 electron volts) and narrow band gap (approximately 1.25 electron volts) perovskite films. HF is composed of a mixture of fullerene (C60), phenyl C61 methyl butyrate, and indene-C60 double adduct, and has improved conductivity, superior energy levels with wide and narrow gap perovskites Alignment and reduced interfacial non-radiative recombination compared to traditional thermal evaporation C60. Using scalable solution-processed HF as ETL, the all-perovskite tandem solar module achieved the highest conversion efficiency of 23.3% (illumination area = 20.25 cm2).
https://onlinelibrar y.wiley.com/doi/full/10.1002/adma.202308706