Formation of a Secondary Phase in Thermally Evaporated MAPbI3 and Its Effects on Solar Cell Performance
Andrés-Felipe Castro-Méndez, Carlo A. R. Perini, Juanita Hidalgo, Daniel Ranke, Jacob N. Vagott, Yu An, Barry Lai, Yanqi Luo, Ruipeng Li, and Juan-Pablo Correa-Baena
ACS Applied Materials & Interfaces Article (2022)
Thermal evaporation is a promising deposition technique to scale up perovskite solar cells (PSCs) to large areas. The lack of understanding of the mechanisms that lead to high-quality evaporated methylammonium lead triiodide (MAPbI3) films gives rise to devices with efficiencies lower than those obtained by spin coating. In this paper, the researchers investigate the role of Sr and Ca-additives on the performance of CsFA-PbI solar cells.
Litos Lite was used to perform parallel JV characterizations for statistical analyses under 1 sun illumination.
Quantum-size-tuned heterostructures enable efficient and stable inverted perovskite solar cells.
Hao Chen, Sam Teale, Bin Chen, Edward H. Sargent, et al.
Nature Photonics 16, 352–358 (2022).
Prof. Ted Sargent and colleagues demonstrated that with big organic molecules such as DMF, it is possible to obtain an inverted perovskite solar cell with a reduced-dimensional perovskite showing a certified efficiency of 23.91%. Without the bulky organics, it is not possible to obtain such efficient inverted pero-PVs with 2D/3D heterostructures due to electron blocking at the 2D/3D interface.
The fabricated devices are also stable. After 500h under ISOS-L3 aging, the encapsulated solar cell lost only 8% of the initial PCE.
This is an outstanding result congratulations to the research team at the University of Toronto.
The Intrinsic Photoluminescence Spectrum of Perovskite Films
Tom P. A. van der Pol, Kunal Datta, Martijn M. Wienk, and René A. J. Janssen
Adv. Optical Mater. (2022), 10, 2102557
Photoluminescence (PL) helps you determine material properties and dynamic effects in perovskite devices. But it is not easy to interpret the PL spectra of perovskites and get to the intrinsic material properties. In this paper, the researchers show you how to do it.
The group of Prof. Rene Janssen at the Eindhoven University of Technology developed an optical model to quantify the intrinsic PL of a perovskite film and determine the influence of the extrinsic factors on the measured PL. The model is based on film thickness, refractive index, extinction coefficient, and carrier diffusion length as input parameters. The authors concluded that the largest mismatch between intrinsic and measured PL is observed for materials with a long diffusion length (>0.5um) and a layer thickness of >300nm.
The simulation software Setfos was instrumental in calculating an accurate emission spectrum to quantify the intrinsic PL for the perovskite. The simulation uses the real nk spectra of the materials and layer thickness as an input, which is the key to resolving the optical system.
The description you find in this paper can be used as a protocol to analyze your PL data on perovskite films.
Perovskite–organic tandem solar cells with indium oxide interconnect.
Brinkmann, K.O., Becker, T., Zimmermann, F. et al.
Nature 604, 280, (2022).
In this Nature paper, Prof. Riedl and colleagues are reporting a new outstanding certified efficiency record of 23.1% with a two-terminal perovskite/organic solar cell.
Thanks to an ALD-deposited InOx interconnection layer, the current between the two subcells is perfectly matched at 14.1 mA/cm2. The high Voc of 2.15 V indicates an almost ideal interconnection between the two subcells. These devices are using an organic absorber for the narrow-gap subcell, which doesn't need the high-temperature processing of silicon and is more stable than the commonly used narrow-bandgap perovskites based on Sn.
With FLUXiM software Setfos, they carried out optical simulations to identify the best wide-bandgap perovskite that matches the organic subcell.