Enhanced optoelectronic coupling for perovskite/silicon tandem solar cells.

Monolithic perovskite/silicon tandem solar cells are of great appeal as they promise high power conversion efficiencies (PCEs) at affordable cost. In state-of-the-art tandems, the perovskite top cell is electrically coupled to a silicon heterojunction bottom cell by means of a self-assembled monolayer (SAM), anchored on a transparent conductive oxide (TCO), which enables efficient charge transfer between the subcells1-3. Yet reproducible, high-performance tandem solar cells require energetically homogeneous SAM coverage, which remains challenging, especially on textured silicon bottom cells. Here, we resolve this issue by using ultrathin (5-nm) amorphous indium zinc oxide (IZO) as the interconnecting TCO, exploiting its high surface-potential homogeneity resulting from the absence of crystal grains and higher density of SAM anchoring sites when compared with commonly used crystalline TCOs. Combined with optical enhancements through equally thin IZO rear electrodes and improved front contact stacks, an independently certified PCE of 32.5% was obtained, which ranks among the highest for perovskite/silicon tandems. Our ultrathin transparent contact approach reduces indium consumption by approximately 80%, which is of importance to sustainable photovoltaics manufacturing4.

Radiative cooling for vertical solar panels.

Radiative cooling presents a method for reducing the operational temperature of solar panels without additional energy consumption. However, its applicability to PV modules has been limited by the thermal properties of existing materials. To overcome these challenges, we introduce a V-shaped design that enhances cooling in vertical PV modules by effectively harnessing thermal radiation from both the front and rear sides, resulting in a substantial temperature reduction of 10.6°C under 1 sun illumination in controlled laboratory conditions. Field tests conducted in warm and humid conditions, specifically in Thuwal, Saudi Arabia, demonstrate a remarkable 15% increase in efficiency while maintaining an operating temperature 0.2°C lower than that of conventional horizontal PV modules, corresponding to a significant 16.8% increase in power output. Our innovative V-shaped design offers a promising thermal strategy suitable for diverse climates, contributing to improved performance and reduced module temperatures, thereby supporting the global pursuit of carbon neutrality.

Pathways toward commercial perovskite/silicon tandem photovoltaics.

Perovskite/silicon tandem solar cells offer a promising route to increase the power conversion efficiency of crystalline silicon (c-Si) solar cells beyond the theoretical single-junction limitations at an affordable cost. In the past decade, progress has been made toward the fabrication of highly efficient laboratory-scale tandems through a range of vacuum- and solution-based perovskite processing technologies onto various types of c-Si bottom cells. However, to become a commercial reality, the transition from laboratory to industrial fabrication will require appropriate, scalable input materials and manufacturing processes. In addition, perovskite/silicon tandem research needs to increasingly focus on stability, reliability, throughput of cell production and characterization, cell-to-module integration, and accurate field-performance prediction and evaluation. This Review discusses these aspects in view of contemporary solar cell manufacturing, offers insights into the possible pathways toward commercial perovskite/silicon tandem photovoltaics, and highlights research opportunities to realize this goal.

Efficient and reliable encapsulation for perovskite/silicon tandem solar modules.

Perovskite/silicon tandem solar cells have a tremendous potential to boost renewable electricity production thanks to their very high performance combined with promising cost structure. However, for actual field deployment, any solar cell technology needs to be assembled into modules, where the associated processes involve several challenges that may affect both the performance and stability of the devices. For instance, due to its hygroscopic nature, ethylene vinyl acetate (EVA) is incompatible with perovskite-based photovoltaics. To circumvent this issue, we investigate here two alternative encapsulant polymers for the packaging of perovskite/silicon tandems into minimodules: a thermoplastic polyurethane (TPU) and a thermoplastic polyolefin (TPO) elastomer. To gauge their impact on tandem-module performance and stability, we performed two internationally established accelerated module stability tests (IEC 61215): damp heat exposure and thermal cycling. Finally, to better understand the thermomechanical properties of the two encapsulants and gain insight into their relation to the thermal cycling of encapsulated tandems, we performed a dynamic mechanical thermal analysis. Our understanding of the packaging process of the tandem module provides useful insights for the development of commercially viable perovskite photovoltaics.

Collaborative Research on Mouth Shape and Lyrics in Singing Practice Based on Image Processing.

Image processing is a mainstream processing method. When people enjoy artists' singing videos, there will be a problem that the subtitles of the lyrics are out of sync with the singer's mouth shape. This problem needs to be solved using image processing technology, letting the computer realize lip-reading recognition function and correct the mouth shape and lyrics subtitles in the image according to the extracted lip-reading data, so that the mouth shape and lyrics in singing practice can be synchronized. Lip-reading information can effectively improve the accuracy of language cognition, save part of capital and manpower investment, and make viewers get a good audio-visual interactive experience. The results show the following: (1) After the UI test, the system user interface function design is reasonable and there is no bad BUG. We can find that the average processing time of each frame is 628 ms, the system performance evaluation is good, and the success rate can be as high as 98.80%. 0.36724 s is the average time for each step when the system processes the image. (2) The human image can basically identify the portrait area and lip area from various angles. (3) Compared with DCT and DWT, the recognition rate of the two cascade lip region feature extraction methods is improved by nearly 10%, and the feature vector dimension is reduced by nearly 65%. (4) Classify the mouth shape more finely and optimize the image of the tester's mouth shape to make the mouth shape closer to the standard mouth shape. (5) After systematic correction of mouth shape and subtitles, the success rate is higher than 90%. Finally, we can find that the running effect is good and the method has achieved high results, which can carry out the details of the next optimization work.

Efficient and stable perovskite-silicon tandem solar cells through contact displacement by MgFx.

The performance of perovskite solar cells with inverted polarity (p-i-n) is still limited by recombination at their electron extraction interface, which also lowers the power conversion efficiency (PCE) of p-i-n perovskite-silicon tandem solar cells. A MgFx interlayer with thickness of ~1 nanometer at the perovskite/C60 interface favorably adjusts the surface energy of the perovskite layer through thermal evaporation, which facilitates efficient electron extraction and displaces C60 from the perovskite surface to mitigate nonradiative recombination. These effects enable a champion open-circuit voltage of 1.92 volts, an improved fill factor of 80.7%, and an independently certified stabilized PCE of 29.3% for a monolithic perovskite-silicon tandem solar cell ~1 square centimeter in area. The tandem retained ~95% of its initial performance after damp-heat testing (85°C at 85% relative humidity) for >1000 hours.

A Highly Conductive Titanium Oxynitride Electron-Selective Contact for Efficient Photovoltaic Devices.

High-quality carrier-selective contacts with suitable electronic properties are a prerequisite for photovoltaic devices with high power conversion efficiency (PCE). In this work, an efficient electron-selective contact, titanium oxynitride (TiOx Ny ), is developed for crystalline silicon (c-Si) and organic photovoltaic devices. Atomic-layer-deposited TiOx Ny is demonstrated to be highly conductive with a proper work function (4.3 eV) and a wide bandgap (3.4 eV). Thin TiOx Ny films simultaneously provide a moderate surface passivation and enable a low contact resistivity on c-Si surfaces. By implementation of an optimal TiOx Ny -based contact, a state-of-the-art PCE of 22.3% is achieved for a c-Si solar cell featuring a full-area dopant-free electron-selective contact. Simultaneously, conductive TiOx Ny is proven to be an efficient electron-transport layer for organic photovoltaic (OPV) devices. A remarkably high PCE of 17.02% is achieved for an OPV device with an electron-transport TiOx Ny layer, which is superior to conventional ZnO-based devices with a PCE of 16.10%. Atomic-layer-deposited TiOx Ny ETL on a large area with a high uniformity may help accelerate the commercialization of emerging solar technologies.

Rapid Synthesis of N-Tosylhydrazones under Solvent-Free Conditions and Their Potential Application Against Human Triple-Negative Breast Cancer.

Some N-tosylhydrazone derivatives were effectively synthesized under solvent-free conditions by using a grinding method at room temperature. The short reaction time, clean and mild process with simple workup and easy purification of the target compounds were salient features of the present protocol, which enables straightforward access to N-tosylhydrazones. Among the tosylhydrazone derivatives evaluated, compound 3 l exhibits excellent apoptosis-promoting and anticancer potential against triple-negative breast cancer (TNBC) cell lines. This research shows that our synthesized compound 3 l may be a desirable and effective therapeutic drug against TNBC.