Chemically Engineered Titanium Oxide Interconnecting Layer for Multijunction Polymer Solar Cells.

We report chemically tunable n-type titanium oxides using ethanolamine as a nitrogen dopant source. As the amount of ethanolamine added to the titanium oxide precursor during synthesis increases, the Fermi level of the resulting titanium oxides (ethanolamine-incorporated titanium oxides) significantly changes from -4.9 eV to -4.

Synthesis and application of amine-containing conjugated small molecules for the automatic formation of an electron transporting layer spontaneous phase separation from the bulk-heterojunction layer.

Carbazole-based conjugated small molecule electrolytes (CSEs) containing different numbers of amine groups were synthesized and applied to bulk-heterojunction (BHJ) organic solar cells for the formation of a spontaneous self-assembled electron transporting layer (ETL). The active layer was spin-coated with a mixture solution containing the BHJ materials and a small amount of CSE, and a thin layer of CSE was formed underneath the active layer (CSE/BHJ bi-layer) spontaneous phase separation, which is confirmed by the depth profile of the time of flight secondary ion mass spectroscopy (ToF-SIMS) spectrum. The amino groups in the CSEs form hydrogen-bonds with the surface of indium tin oxide (ITO), which acts as an ETL in BHJ solar cells.

High-efficiency large-area perovskite photovoltaic modules achieved via electrochemically assembled metal-filamentary nanoelectrodes.

Realizing industrial-scale, large-area photovoltaic modules without any considerable performance losses compared with the performance of laboratory-scale, small-area perovskite solar cells (PSCs) has been a challenge for practical applications of PSCs. Highly sophisticated patterning processes for achieving series connections, typically fabricated using printing or laser-scribing techniques, cause unexpected efficiency drops and require complicated manufacturing processes. We successfully fabricated high-efficiency, large-area PSC modules using a new electrochemical patterning process.

Achieving Large-Area Planar Perovskite Solar Cells by Introducing an Interfacial Compatibilizer.

Despite the recent unprecedented increase in the power conversion efficiencies (PCEs) of small-area devices (≤0.1 cm ), the PCEs deteriorate drastically for PSCs of larger areas because of the incomplete film coverage caused by the dewetting of the hydrophilic perovskite precursor solutions on the hydrophobic organic charge-transport layers (CTLs). Here, an innovative method of fabricating scalable PSCs on all types of organic CTLs is reported.

High-Performance Integrated Perovskite and Organic Solar Cells with Enhanced Fill Factors and Near-Infrared Harvesting.

Highly efficient P-I-N type perovskite/bulk-heterojunction (BHJ) integrated solar cells (ISCs) with enhanced fill factor (FF) (≈80%) and high near-infrared harvesting (>30%) are demonstrated by optimizing the BHJ morphology with a novel n-type polymer, N2200, and a new solvent-processing additive. This work proves the feasibility of highly efficient ISCs with panchromatic absorption as a new photovoltaic architecture and provides important design rules for optimizing ISCs.

Long-Term Stable Recombination Layer for Tandem Polymer Solar Cells Using Self-Doped Conducting Polymers.

Unlabelled: Recently, the most efficient tandem polymer solar cells (PSCs) have used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (

Pedot: PSS) as a p-type component of recombination layer (RL). However, its undesirable acidic nature, originating from insulating PSS, of

Pedot: PSS drastically reduces the lifetime of PSCs. Here, we demonstrate the efficient and stable tandem PSCs by introducing acid-free self-doped conducting polymer (SCP), combined with zinc oxide nanoparticles (ZnO NPs), as RL for

Pedot: PSS-free tandem PSCs.

A series connection architecture for large-area organic photovoltaic modules with a 7.5% module efficiency.

The fabrication of organic photovoltaic modules via printing techniques has been the greatest challenge for their commercial manufacture. Current module architecture, which is based on a monolithic geometry consisting of serially interconnecting stripe-patterned subcells with finite widths, requires highly sophisticated patterning processes that significantly increase the complexity of printing production lines and cause serious reductions in module efficiency due to so-called aperture loss in series connection regions. Herein we demonstrate an innovative module structure that can simultaneously reduce both patterning processes and aperture loss.

Long-term stable polymer solar cells with significantly reduced burn-in loss.

The inferior long-term stability of polymer-based solar cells needs to be overcome for their commercialization to be viable. In particular, an abrupt decrease in performance during initial device operation, the so-called 'burn-in' loss, has been a major contributor to the short lifetime of polymer solar cells, fundamentally impeding polymer-based photovoltaic technology. In this study, we demonstrate polymer solar cells with significantly improved lifetime, in which an initial burn-in loss is substantially reduced.

Soluble transition metal oxide/polymeric acid composites for efficient hole-transport layers in polymer solar cells.

We report a new method for developing a low-temperature solution processed vanadium oxide (s-VOx) and poly(4-styrene sulfonic acid) (PSS) composite to act as an efficient hole-transport layer (HTL) in polymer solar cells (PSCs). By compositing the s-VOx and PSS (s-VOx:PSS), the work function values of the s-VOx:PSS changed from 5.0 to 5.

A new architecture for printable photovoltaics overcoming conventional module limits.

A new architecture for manufacturing large-area polymer solar cells that does not produce concomitant aperture and Ohmic losses is presented. By introducing the innovative concept of metal-filamentary nanoelectrodes, which are vertically formed inside the main active layers, loss-free, widely expandable solar cells with the highest relative power conversion efficiency (ca. 90%) in organic photovoltaic systems are demonstrated.