Enhancing fully printable mesoscopic perovskite solar cell performance using integrated metallic grids to improve carbon electrode conductivity, Current Applied Physics (2020), doi:

Since their advent in 2009, lead halide perovskite solar cells (PSCs) have rapidly progressed to exhibit power conversion efficiencies (PCEs) of 25.5%, approaching that of commercially available monocrystalline silicon devices. [1][2][3][4] In addition to exhibiting excellent carrier mobility, high absorption coefficients, tunable bandgaps, and unusual defect tolerance, these semiconductors are cheap and amenable to low-cost solution-based processing. [5][6][7][8] To be considered commercially viable, stable, high-efficiency devices must be easily and reproducibly attainable at large scale for low-cost per watt peak. PSC commercialization is currently limited by poor device stability under operating conditions; perovskites are particularly sensitive to humidity as well as exhibiting UV, thermal, and oxygen sensitivity in many architectures. [9][10][11][12] In addition, many device architectures use prohibitively expensive or toxic components or manufacturing methods inherently unsuitable for large-scale production. Expensive and unstable organic hole extraction materials (HTMs) such as spiro-OMeTAD are particularly problematic. This has led to significant research on alternative materials such as NiO and work on hole conductor free carbon-based devices with improved operational stability. [13][14][15][16] Mesoscopic carbon-based perovskite solar cells (CPSCs) make use of easily scaled manufacturing processes and are frequently described as one of the frontrunners for perovskite commercialization. Fabricated via sequential screen printing of mesoporous TiO 2 , ZrO 2 , and carbon before drop casting of the perovskite precursor, CPSCs are highly stable, benefitting from both the lack of a hole transporter and the presence of a >20 μm-thick, encompassing mesoporous scaffold, which provides mechanical stability and limits oxygen and moisture access. [17] Performance and stability are further enhanced by incorporating 5-aminovaleric acid (AVAI) to improve precursor infiltration, induce highly stable 2D/3D crystal formations at the perovskiteÀTiO 2 interface, and limit superoxide production. [17,18] Polyurethane/glassencapsulated devices produced using AVA (x) MA (1Àx) PbI 3 γ-butyrolactone (GBL) perovskite precursors recently passed stringent IEC61215:2016 tests, including damp heat tests (85 C at 85% relative humidity (RH), for 1100 h), thermal cycling tests (À40 to 85 C for 200 cycles), UV preconditioning tests (60 C, 50 kWh m À2 ), and maximum power point testing light-soaking tests (55 C, 9000 h). [19] This impressive stability combined with the use of scalable deposition techniques make CPSCs attractive for commercial development, and manufacturing bottlenecks are already being addressed in the scientific literature, for example, using nearinfrared annealing and robotic infiltration methods to drastically reduce heating times and automate infiltration. [18,20,21] However, significant barriers to commercial application still exist. [22,23] For example, the most common precursor solvents for CPSCs, dimethylformamide...

Perovskite solar cells (PSCs) have already achieved comparable performance to industrially established silicon technologies. However, high performance and stability must be also be achieved at large area and low cost to be truly commercially viable. The fully printable triple-mesoscopic carbon perovskite solar cell (mCPSC) has demonstrated unprecedented stability and can be produced at low capital cost with inexpensive materials. These devices are inherently scalable, and large-area modules have already been fabricated using low-cost screen printing. As a uniquely stable, scalable and low-cost architecture, mCPSC research has advanced significantly in recent years. This review provides a detailed overview of advancements in the materials and processing of each individual stack layer as well as in-depth coverage of work on perovskite formulations, with the view of highlighting potential areas for future research. Long term stability studies will also be discussed, to emphasise the impressive achievements of mCPSCs for both indoor and outdoor applications.

We present an attractive method for the fabrication of long, straight, highly crystalline, ultrathin platinum nanowires. The fabrication is simply achieved using an inverse hexagonal (H) lyotropic liquid crystal phase of the commercial surfactant phytantriol as a template. A platinum precursor dissolved within the cylindrical aqueous channels of the liquid crystal phase is chemically reduced by galvanic displacement using stainless steel. We demonstrate the production of nanowires using the H phase in the phytantriol/water system which we obtain either by heating to 55 °C or at room temperature by the addition of a hydrophobic liquid, 9- cis-tricosene, to relieve packing frustration. The two sets of conditions produced high aspect nanowires with diameters of 2.5 and 1.7 nm, respectively, at least hundreds of nanometers in length, matching the size of the aqueous channels in which they grow. This versatile approach can be extended to produce highly uniform nanowires from a range of metals.

Mesoscopic carbon-based perovskite solar cells (CPSCs) are frequently described as a potential frontrunner for PSC commercialization. Previous work has introduced γ-valerolactone (GVL) as a sustainable, non-toxic, green alternative to GBL...