Monolithic Two-Terminal Perovskite/Perovskite/Silicon Triple-Junction Solar Cells with Open Circuit Voltage >2.8 V.

The efficiency of perovskite/silicon tandem solar cells has exceeded the previous record for III-V-based dual-junction solar cells. This shows the high potential of perovskite solar cells in multi-junction applications. Perovskite/perovskite/silicon triple-junction solar cells are now the next step to achieve efficient and low-cost multi-junction solar cells with an efficiency potential even higher than that for dual-junction solar cells.

Vapor-Phase Formation of a Hole-Transporting Thiophene Polymer Layer for Evaporated Perovskite Solar Cells.

Homogeneous layer formation on textured silicon substrates is essential for the fabrication of highly efficient monolithic perovskite silicon tandem solar cells. From all well-known techniques for the fabrication of perovskite solar cells (PSCs), the evaporation method offers the highest degree of freedom for layer-by-layer deposition independent of the substrate's roughness or texturing. Hole-transporting polymers with high hole mobility and structural stability have been used as effective hole-transporting materials (HTMs) of PSCs.

Semi-Transparent Perovskite Solar Cells with ITO Directly Sputtered on Spiro-OMeTAD for Tandem Applications.

Perovskite silicon tandem solar cells have the potential to overcome the efficiency limit of single-junction solar cells. For both monolithic and mechanically stacked tandem devices, a semi-transparent perovskite top solar cell, including a transparent contact, is required. Usually, this contact consists of a metal oxide buffer layer and a sputtered transparent conductive oxide.

Efficiency Enhancement and Hysteresis Mitigation by Manipulation of Grain Growth Conditions in Hybrid Evaporated-Spin-coated Perovskite Solar Cells.

Perovskite solar cells have become a game changer in the field of photovoltaics by reaching power conversion efficiencies beyond 23%. To achieve even higher efficiencies, it is necessary to increase the understanding of crystallization, grain formation, and layer ripening. In this study, by a systematic variation of methylammonium iodide (MAI) concentrations, we changed the stoichiometry and thereupon the crystal growth conditions in MAPbI perovskite solar cells, prepared by a two-step hybrid evaporation-spin-coating deposition method.

Detailed Investigation of Evaporated Perovskite Absorbers with High Crystal Quality on Different Substrates.

Dual-source vapor-phase deposition enables low-temperature fabrication of high-performance planar structure perovskite (CHNHPbI) solar cells (PSCs), applicable in tandem devices or for industrial production with high homogeneity. Herein, we report low-temperature fabrication of high-efficiency PSCs by dual-source vapor-phase deposition and significance of TiO surface modification with [6,6]-phenyl C butyric acid methyl ester (PCBM) on cell performance. Co-evaporation of PbI and CHNHI, as confirmed by X-ray diffraction and high-resolution transmission electron microscopy analyses, results in CHNHPbI layers with a well-crystallized tetragonal phase formed on both TiO and TiO/PCBM electron-transport layers (ETLs).

Novel Low-Temperature Process for Perovskite Solar Cells with a Mesoporous TiO Scaffold.

The most efficient organic-inorganic perovskite solar cells (PSCs) contain the conventional n-i-p mesoscopic device architecture using a semiconducting TiO scaffold combined with a compact TiO blocking layer for selective electron transport. These devices achieve high power conversion efficiencies (15-22%) but mainly require high-temperature sintering (>450 °C), which is not possible for temperature-sensitive substrates. Thus far, comparably little effort has been spent on alternative low-temperature (<150 °C) routes to realize high-efficiency TiO-based PSCs; instead, other device architectures have been promoted for low-temperature processing.

Wave optical simulation of the light trapping properties of black silicon surface textures.

Due to their low reflectivity and effective light trapping properties black silicon nanostructured surfaces are promising front side structures for thin crystalline silicon solar cells. For further optimization of the light trapping effect, particularly in combination with rear side structures, it is necessary to simulate the optical properties of black silicon. Especially, the angular distribution of light in the silicon bulk after passage through the front side structure is relevant.