Ultra-uniform perovskite crystals formed in the presence of tetrabutylammonium bistriflimide afford efficient and stable perovskite solar cells.

Compositional engineering of organic-inorganic metal halide perovskite allows for improved optoelectrical properties, however, phase segregation occurs during crystal nucleation and limits perovskite solar cell device performance. Herein, we show that by applying tetrabutylammonium bistriflimide as an additive in the perovskite precursor solution, ultra-uniform perovskite crystals are obtained, which effectively increases device performance. As a result, power conversion efficiencies (PCEs) of 24.

Remanufacturing Perovskite Solar Cells and Modules-A Holistic Case Study.

While perovskite photovoltaic (PV) devices are on the verge of commercialization, promising methods to recycle or remanufacture fully encapsulated perovskite solar cells (PSCs) and modules are still missing. Through a detailed life-cycle assessment shown in this work, we identify that the majority of the greenhouse gas emissions can be reduced by re-using the glass substrate and parts of the PV cells. Based on these analytical findings, we develop a novel thermally assisted mechanochemical approach to remove the encapsulants, the electrode, and the perovskite absorber, allowing reuse of most of the device constituents for remanufacturing PSCs, which recovered nearly 90% of their initial performance.

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.

Hydrophobic AlO Surfaces by Adsorption of a SAM on Large Areas for Application in Solar Cell Metallization Patterning.

A resist-free metallization of copper-plated contacts is attractive to replace screen-printed silver contacts and is demonstrated on large-area silicon heterojunction (SHJ) solar cells. In our approach, a self-passivated Al layer is used as a mask during the plating process. In this study, Al/AlO or AlO plating masks are further functionalized by a self-assembled monolayer (SAM) of octadecyl phosphonic acid (ODPA).

In Situ Surface Temperature Measurement in a Conveyor Belt Furnace via Inline Infrared Thermography.

Measuring the surface temperature of objects that are processed in conveyor belt furnaces is an important tool in process control and quality assurance. Currently, the surface temperature of objects processed in conveyor belt furnaces is typically measured via thermocouples. However, infrared (IR) thermography presents multiple advantages compared to thermocouple measurements, as it is a contactless, real-time, and spatially resolved method.

Tailored disorder: a self-organized photonic contact for light trapping in silicon-based tandem solar cells.

We present a process development leading to efficient rear side light trapping structures with the purpose of enhancing the infrared response of a silicon-based tandem solar cell. To this end, we make use of phase separation effects of two immiscible polymers, polystyrene and poly(methyl methacrylate), resulting in a non-periodic polystyrene structure on silicon with a well-defined size distribution. Onto this pattern, we evaporate silver as a scattering rear side mirror and contact layer.

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.

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).

Distinguishing crystallization stages and their influence on quantum efficiency during perovskite solar cell formation in real-time.

Relating crystallization of the absorber layer in a perovskite solar cell (PSC) to the device performance is a key challenge for the process development and in-depth understanding of these types of high efficient solar cells. A novel approach that enables real-time photo-physical and electrical characterization using a graphite-based PSC is introduced in this work. In our graphite-based PSC, the device architecture of porous monolithic contact layers creates the possibility to perform photovoltaic measurements while the perovskite crystallizes within this scaffold.

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.

UV Degradation and Recovery of Perovskite Solar Cells.

Although the power conversion efficiency of perovskite solar cells has increased from 3.81% to 22.1% in just 7 years, they still suffer from stability issues, as they degrade upon exposure to moisture, UV light, heat, and bias voltage.

Illumination-induced errors associated with suns-V(OC) measurements of silicon solar cells.

I(SC)-V(OC) curves measured by the suns-V(OC) method are widely used for solar cell characterization due to its being unaffected by series resistance effects. A common setup for this measurement system uses a xenon photoflash for illumination purposes, resulting in a fast acquisition of the suns-V(OC) measurement data during the decaying edge of one flash. However, the use of a xenon photoflash accompanies also several disadvantages.