Standard Illumination Research Articles

Enhancing Photovoltaic Performance and Stability of Perovskite Solar Cells through Single-Source Evaporation and CsPbBr3 Quantum Dots Incorporation

This study investigates the potential of inorganic perovskite CsPbBr3 as a photovoltaic material, highlighting its superior stability compared to that of organic–inorganic hybrid perovskite materials. Conventional methods for preparing CsPbBr3 perovskite films, such as the two-step method and the dual-source thermal evaporation method, face challenges in obtaining high-purity films due to the decomposition of precursor films and the formation of multiple heterogeneous phases. To address this issue, we synthesized CsPbBr3 powder material using thermal evaporation deposition, which effectively suppressed decomposition and the formation of heterogeneous phases. Consequently, we achieved uniform and dense CsPbBr3 perovskite films. By incorporating energy-band engineering modification with CsPbBr3 quantum dots (QDs), the all-inorganic perovskite solar cells (PSCs) attained a power conversion efficiency (PCE) of 7.01% under standard solar illumination conditions. The device PCE remained at 93% of its initial efficiency under 30% relative humidity conditions for over 100 days, showcasing its durability. The developed method produced an average grain size of 800 nm, resulting in a smooth and uniform film surface, thereby demonstrating the method’s high repeatability. Additionally, the optimized PSCs exhibited a high open-circuit voltage (VOC) with the champion device reaching a VOC of 1.38 V and a PCE of 7.01%. This research presents a robust, efficient, and cost-effective approach for fabricating high-quality all-inorganic PSCs.

Biosynthesis, characterization and optimization of TiO2 nanoparticles by novel marine halophilic Halomonas sp. RAM2: application of natural dye-sensitized solar cells

BackgroundMetal oxide nanoparticles (NPs) are becoming valuable due to their novel applications. The green synthesis of TiO2 NPs is more popular as a flexible and eco-friendly method compared to traditional chemical synthesis methods. TiO2 NPs are the most commonly used semiconductor in dye-sensitized solar cells (DSSCs).ResultsThe biogenic TiO2 NPs were produced extracellularly by the marine halophilic bacterium Halomonas sp. RAM2. Response surface methodology (RSM) was used to optimize the biosynthesis process, resulting in a starting TiO2 concentration of 0.031 M and a pH of 5 for 92 min (⁓15 nm). TiO2 NPs were well-characterized after the calcination process at different temperatures of 500, 600, 700 and 800 °C. Anatase TiO2 NPs (calcined at 500 °C) with a smaller surface area and a wider bandgap were nominated for use in natural dye-sensitized solar cells (NDSSCs). The natural dye used as a photosensitizer is a mixture of three carotenoids extracted from the marine bacterium Kocuria sp. RAM1. NDSSCs were evaluated under standard illumination. After optimization of the counter electrode, NDSSCBio(10) (10 layers) demonstrated the highest photoelectric conversion efficiency (η) of 0.44%, which was almost as good as NDSSCP25 (0.55%).ConclusionThe obtained results confirmed the successful green synthesis of TiO2 NPs and suggested a novel use in combination with bacterial carotenoids in DSSC fabrication, which represents an initial step for further efficiency enhancement studies.

Photo-electrocatalytic based removal of acetaminophen: Application of visible light driven heterojunction based BiVO4/BiOI photoanode

The presence of organic micro-pollutants (OMPs) in wastewater treatment effluents is becoming a major threat to the water safety for aquatic and human health. Photo-electrocatalytic based advanced oxidation process (AOP) is one of the emerging and effective techniques to degrade OMPs through oxidative mechanism. This study investigated the application of heterojunction based BiVO4/BiOI photoanode for acetaminophen (40 μg L−1) removal in demineralized water. Photoanodes were fabricated by electrodeposition of BiVO4 and BiOI photocatalytic layers. Optical (UV–vis diffusive reflectance spectroscopy), structural (XRD, SEM, EDX) and opto-electronic (IPCE) characterization confirmed the successful formation of heterojunction for enhanced charge separation efficiency. The heterojunction photoanode showed incident photon to current conversion efficiency of 16% (λmax = 390 nm) at an external voltage of 1 V under AM 1.5 standard illumination. The application of the BiVO4/BiOI photoanode in the removal of acetaminophen at 1 V (external bias) vs Ag/AgCl under simulated sunlight showed 87% removal efficiency within the first 120 min compared to 66% removal efficiency of the BiVO4 photoanode. Similarly, combining BiVO4 and BiOI exhibited 57% increase in first order removal rate coefficient compared to BiVO4. The photoanodes also showed moderate stability and reusability by showing 26% decrease in overall degradation efficiency after three cycles of each 5 h experiment. The results obtained in this study can be considered as a stepping stone towards the effective removal of acetaminophen as an OMP present in wastewater.

Method to Calculate Melanopic Light Reaching the Retina Depending on the Optical Density of an Aging Crystalline Lens

Lighting studies that take into account the age of the inhabitants of an area and are related to circadian light are difficult to find. This study aims to simplify a method to approximately compute the circadian light reaching the retina based on photopic illuminance reaching the corneal plane and considering the optical density of an aging crystalline lens. As an example of this proposed method, calculations were performed with both the D65 and A standard illuminants, showing how the spectral power distribution is modified by the optical density of the crystalline lens, mainly at short wavelengths. Due to these selective wavelength absorptions of the aged lens, a significant variation in the level of daylight equivalent melanopic illuminance (EDI) is present in the retina. With levels of 200 lux at the corneal plane, these variations ranged from 204 EDI lux to 178 EDI lux for the D65 standard illuminant, and from 99 EDI lux to 101 EDI lux for the A standard illuminant for observers aged 10 and 90, respectively. In this work, we aimed to simplify the greatest possible level of calculation of melanopic light, while describing simple protocols that are easy to translate into practice. Our results will allow researchers to carry out optimized lighting designs from both the photometric and circadian perspectives considering the optical density of an aging lens.

Controlled growth of perovskite layers with volatile alkylammonium chlorides.

Controlling the crystallinity and surface morphology of perovskite layers by methods such as solvent engineering1,2 and methylammonium chloride addition3-7 is an effective strategy for achieving high-efficiency perovskite solar cells. In particular, it is essential to deposit α-formamidinium lead iodide (FAPbI3) perovskite thin films with few defects due to their excellent crystallinity and large grain size. Here we report the controlled crystallization of perovskite thin films with the combination of alkylammonium chlorides (RACl) added to FAPbI3. The δ-phase to α-phase transition of FAPbI3 and the crystallization process and surface morphology of the perovskite thin films coated with RACl under various conditions were investigated through in situ grazing-incidence wide-angle X-ray diffraction and scanning electron microscopy. RACl added to the precursor solution was believed to be easily volatilized during coating and annealing owing to dissociation into RA0 and HCl with deprotonation of RA+ induced by RA⋯H+-Cl- binding to PbI2 in FAPbI3. Thus, the type and amount of RACl determined the δ-phase to α-phase transition rate, crystallinity, preferred orientation and surface morphology of the final α-FAPbI3. The resulting perovskite thin layers facilitated the fabrication of perovskite solar cells with a power-conversion efficiency of 26.08% (certified 25.73%) under standard illumination.

Physiological state of chickens cross dekalb white depending on the conditions of detention

The functional state of the heart, liver and kidneys of Dekalb White cross chickens kept for 13 weeks under different light conditions was assessed. The study was carried out in the Department of Аnimal Husbandry and Poultry Federal State Budgetary Scientific Institution Far East Zone Research Veterinary Institute and Department of Physiology and Pathophysiology FSBEI HE Amur SMA MOH Russia, Blagoveshchensk, Amur region, Russia. In the conditions of the Belogorskaya poultry farm of the Amur region, chickens were kept in cell batteries from the age of 3 weeks at standard (6-10 lux) and brighter (40-50 lux) illumination. During the experiment, laboratory diagnostics of the blood of birds aged 4, 9, 12 and 16 weeks was carried out. 60 young laying hens aged 16 weeks were taken for anatomical examination, macro- and micromorphological examination of the heart, liver and kidneys was performed. It was revealed that at a low level of illumination (6-10 lux), the amount of hemoglobin in the blood of chickens decreased by 5,5-12,5% and erythrocytes by 4,2-15,5%, from 9 weeks of age, the amount of glucose decreased by 29,7% compared to the norm with an increase in the level of gamma globulins by 17,4-48,2%, bilirubin by 2,9 times, aspartate aminotransferase by 2,5 times, alanine aminotransferase by 2,2 times, creatinine by 63,7% higher than normal, at 16 weeks of age, an increase in absolute weight right ventricle of the heart by 4,5%, interventricular septum by 22,2%, epicardial fat by 11,0% and abdominal fat by 17,4%. In chickens with illumination of 40-50 lux, the established deviations were less significant, microscopy showed an increase in the area of the lumen of the arterial vessels by 27,1% in the myocardium and 5,7% in the hepatic lobules, a decrease in the area of the juxtamedullary glomeruli by 5,9%, the area of the lumen of the proximal and distal tubules of nephrons by 8,6-33,7%, indicating an improvement in the functional state of the heart, liver and kidneys.

Programmable, high-speed, adaptive optics partially confocal multi-spot ophthalmoscope using a digital micromirror device.

A high-speed, adaptive optics partially confocal multi-spot ophthalmoscope (AO-pcMSO) using a digital micromirror device (DMD) in the illumination channel and a fast 2D CMOS camera is described. The camera is synchronized with the DMD allowing projection of multiple, simultaneous AO-corrected spots onto the human retina. Spatial filtering on each raw retinal image before reconstruction works as an array virtual pinholes. A frame acquisition rate of 250 fps is achieved by applying this parallel projection scheme. The contrast improves by 2-3 fold when compared to a standard flood illumination architecture. Partially confocal images of the human retina show cone and rod photoreceptors over a range of retinal eccentricities.

Image color-based preset light matching algorithm for an electric vitrine

Recent advanced light systems offer light presets to enable users to navigate a proper light. Often, the presets are labeled with target ambiance or mood, yet ambiguous for users to predict the light. This study proposes an algorithm that matches the light presets based on the image color characteristics derived from a photograph taken by users. In particular, we developed an automatic match of a light preset for an electric vitrine in which 15 RGB LEDs were linearly arrayed beneath the cover. We conducted a creativity workshop with eight light designers and composed a pool of 22 light presets for the electric vitrine. The presets attempted to cover five standard illuminants, eleven chromatic lights, and six kinds of the color spectrum. The algorithm enables users to receive the optimally matched light presets in order of hue similarities between displayed objects and the light preset. Based on stakeholders’ feedback, the algorithm UX is designed to provide three alternatives made up of the best chromatic light color, the best standard illuminant, and the best color spectrum. We expect the algorithm to be applied to different contexts, where light needs to be optimally tuned by being aware of the context characteristics.

Stitching Perovskite Grains with Perhydropoly(Silazane) Anti‐Template‐Agent for High‐Efficiency and Stable Solar Cells Fabricated in Ambient Air

All inorganic CsPbI3perovskite solar cells (PSCs) have emerged as disruptive photovoltaic technology owing to their admirable photoelectric properties and the non‐volatile active layer. However, the phase instability against moisture severely limits the fabrication environment for the high‐efficiency devices, breaking through the confinement region to achieve scalable manufacturing has been the primary issue for future commercialization. Here, we develop a curing‐anti‐solvent strategy for fabricating high‐quality and stable black‐phase CsPbI3perovskite films in ambient air by introducing an inorganic polymer perhydropolysilazane (PHPS) into methyl acetate to form anti‐template agent. The cross‐linked PHPS reduces moisture erosions while the hydrolyzate silanol network (–Si(OH)4–) controls the perovskite crystal growth by forming Lewis adducts with PbI2during the fabrication. The polycondensation adduct of Si–O–Si/Si–O–Pb strongly binds to CsPbI3grains as a shield layer to hamper phase transition. Using the inorganic CsPbI3perovskite thin‐film with PHPS‐modified anti‐solvent processing as the light absorber, the n–i–p planar solar cell achieved an efficiency of 19.17% under standard illumination test conditions. More importantly, the devices showed excellent moisture stability, retaining about 90% of the initial efficiency after 1000 h under 30% RH.

Incorporating formamidinium into 4-fluoro-phenethylammonium based quasi-2D perovskite films and their application in n-i-p perovskite solar cells

Recently, perovskite solar cells (PSCs) basing on quasi-two-dimensional (quasi-2D) perovskites with hydrophobic bulky organic cations have received a lot of interests owing to their superior moisture stability. While quasi-2D perovskites have achieved great success in planar p-i-n PSCs, their application in planar n-i-p devices and the corresponding efficiencies lag far behind. In our work, (FPEA)2(MA)4Pb5I16 perovskite films with high crystallinity, compact and smooth surface were deposited on electron transport layer with NH4SCN as an additive. Formamidinium (FA+) were then incorporated into the FPEA based perovskite films to partially replace methylammonium (MA+), and effects of FA+ on the film's vertical orientation, light absorption capacity, carrier lifetime, defect density and electron mobility were studied. It was found that when molar ratio of FA/MA = 0.5/9.5, the film had the highest vertical orientation, enhanced light absorption, less carrier recombination loss. The obtained (FPEA)2(FA0.05MA0.95)4Pb5I16 based n-i-p PSCs gave a maximum efficiency of 12.17% under standard illumination, retaining 83% of the initial efficiency after stored in air environment (25–30 °C) with 40 ± 5% RH for 1080 h. The results demonstrate an efficient approach to prepare high-quality quasi-2D perovskite films in a n-i-p structure as well as improved device efficiency and stability.

Magnetic field modulation of photocurrent in BiFeO<sub>3</sub> film

BiFeO<sub>3</sub> (BFO) is a kind of room temperature multiferroic material with bulk photovoltaic effect, and it has been a research hotspot in the field of multifunctional materials in recent years. The coexistence of the coupling among magnetic, optical, electrical properties brings rich and complex physical connotations. In this work, BiFeO<sub>3</sub> thin film is deposited on FTO substrate by pulsed laser deposition, and the solar cell structure with BiFeO<sub>3</sub> film used as light absorption layer and Au film serving as electrode is constructed. X-ray diffraction and Raman spectra indicate that the BFO film grown on FTO substrate has a pure phase structure. The experimental results of physical properties indicate that the BFO film possesses good ferromagnetic and ferroelectric properties and obvious photoelectric effect. According to the hysteresis loop, the remanence (<i>M</i><sub>r</sub>) of the sample is 0.8 emu/cm<sup>3</sup>, and the coercivity (<i>H</i><sub>c</sub>) is 200 Oe at 300 K. In terms of ferroelectricity, the saturation polarization intensity of the sample can reach 0.997 μC/cm<sup>2</sup>, the residual polarization intensity is 0.337 μC/cm<sup>2</sup>, and the coercive electric field is 12.45 kV/cm. The above results show that the BFO film has good multiferroic properties. Under solar illumination conditions, the photocurrent density up to 208 mA/cm<sup>2</sup> is obtained when a bias voltage 1 V is applied. More importantly, magneto-photocurrent (MPC) effect is found in the BFO film. No matter whether the magnetic field starts to increase from the positive direction or the negative direction, the MPC usually changes with the magnitude of magnetization. When a 1.3 kOe magnetic field is applied, the magneto-photocurrent change rate up to 232.7% is observed under standard solar illumination condition. The results show that the photocurrent of BFO films is greatly improved by a positive magnetic field and negative magnetic field. This magneto-photocurrent effect in BFO thin film comes from the photo-magnetoresistance effect, that is, the photogenerated electrons become spin photoelectrons under the action of an external magnetic field and receive spin-dependent scattering during moving in the conductive band of the material, thus producing the photo-magnetoresistance effect. In addition, the magneto-photocurrent effect is further enhanced by weakening the domain wall scattering of the spin electrons by the magnetic field. This work provides a reference for the modulation effect of magnetic field and light field on the magnetic, optical and electrical properties in multiferroics, and presents a foundation for the research and application of devices in the field of multifunctional optoelectronic materials.

Electrical passivation of III-V multijunction solar cells with luminescent coupling effect

Perimeter recombination is one of the causes identified for having a nonuniform luminescent coupling effect in III-V multijunction solar cells. A potential solution could be the electrical passivation of the multijunction solar cell perimeter. To test this hypothesis, electrical passivation of InGaP/GaAs/Ge 3-junction solar cells was done by the atomic layer deposition of thin Al 2 O 3 films. Perimeter passivation of a 3-junction solar cell relatively increased current collection measured at luminescent coupling and direct subcell excitation by as much as 11.4% and 29.8%, respectively. Meanwhile, the current homogeneity improved relatively by as much as 7.9% after electrical passivation. At 1-sun global standard illumination (AM 1.5G), 0.2% absolute conversion efficiency increase was achieved. Therefore, electrical passivation of fully working III-V multijunction solar cells is a non-invasive, post-treatment process that can recover losses due to surface defects caused by oxidation. • Post-treatment passivation for fully working multijunction solar cell. • Larger conversion efficiencies in multijunction solar cells with smaller active areas. • Spatial current uniformity improvement after perimeter passivation. • Reduction of shunt leakage current in a subcell made of indirect bandgap material. • Alleviate lateral resistance effects by electrical passivation.

Influence of the carbazole moiety in self-assembling molecules as selective contacts in perovskite solar cells: interfacial charge transfer kinetics and solar-to-energy efficiency effects.

The use of self-assembled molecules (SAMs) as hole transport materials (HTMs) in p-i-n perovskite solar cells (iPSCs) has triggered widespread research due to their relatively easy synthetic methods, suitable energy level alignment with the perovskite material and the suppression of chemical defects. Herein, three new SAMs have been designed and synthesised based on a carbazole core moiety and modified functional groups through an efficient synthetic protocol. The SAMs have been used to understand the SAM/perovskite interface interactions and establish the relationship between the SAM molecular structure and the resulting performance of the perovskite-based devices. The best devices show efficiencies ranging from 18.9% to 17.5% under standard illumination conditions, which are very close to that of our benchmark EADR03, which has been recently commercialised. Our work aims to provide knowledge on the structure of the molecules versus device function relationship.

Broadband photodetection using one-step CVD-fabricated MoS2/MoO2 microflower/microfiber heterostructures

Molybdenum disulfide (MoS2) has been combined so far with other photodetecting semiconductors as an enhancing agent owing to its optical and electronic properties. Existing approaches demonstrated MoS2-incorporated photodetector devices using complex and costly fabrication processes. Here, we report on simplified one-step on the chemical vapor deposition (CVD) based synthesis of a unique microfiber/microflower MoS2-based heterostructure formed by capturing MoO2 intermediate material during the CVD process. This particular morphology engenders a material chemical and electronic interplay exalting the heterostructure absorption up to ~ 98% over a large spectral range between 200 and 1500 nm. An arsenal of characterization methods were used to elucidate the properties of these novel heterostructures including Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectrometry, high-resolution transmission and scanning electron microscopies, and Kelvin probe force microscopy. Our findings revealed that the MoS2 and the MoO2 crystallize in the hexagonal and monoclinic lattices, respectively. The integration of the MoS2/MoO2 heterostructures into functional photodetectors revealed a strong photoresponse under both standard sun illumination AM1.5G and blue light excitation at 450 nm. Responsivity and detectivity values as high as 0.75 mA W−1 and 1.45 × 107 Jones, respectively, were obtained with the lowest light intensity of 20 mW cm−2 at only 1 V bias. These results demonstrate the high performances achieved by the unique MoS2/MoO2 heterostructure for broadband light harvesting and pave the way for their adoption in photodetection applications.

Improving charge transfer in phosphate ion-modified hematite photoanode via decoration with gold nanostructures

Herein, we report a unique synergistic behavior between the phosphate ions (Pi) layer and the plasmonic gold nanostructures to enhance the PEC performance of the hematite photoanode. Under such a combined effect, the lifetime of the photogenerated holes is enhanced by a factor of 3-fold relative to that of pristine hematite. The Au/Pi–hematite photoanode illustrates a stable photocurrent of 1.32 mA cm–2 at 1.23 VRHE under standard illumination conditions, which is 3.1, 2.1, and 1.7 times higher than those of pristine hematite, Au/hematite, and Pi–modified hematite photoanodes, respectively. The enhanced photocurrent of Au/Pi–hematite is attributed to the improved hole lifetime and charge transfer kinetics as confirmed by transient photocurrent (TPC), photoelectrochemical impedance spectroscopy (PEIS), and intensity-modulated photocurrent spectroscopy (IMPS) measurements. Au nanostructures have a dual function. They enhance the light absorption ability and more importantly improve the charge transfer efficiency.

QRsens: Dual-purpose quick response code with built-in colorimetric sensors

QRsens represents a family of Quick Response (QR) sensing codes for in-situ air analysis with a customized smartphone application to simultaneously read the QR code and the colorimetric sensors. Five colorimetric sensors (temperature, relative humidity (RH), and three gas sensors (CO2, NH3 and H2S)) were designed with the aim of proposing two end-use applications for ambient analysis, i.e., enclosed spaces monitoring, and smart packaging. Both QR code and colorimetric sensing inks were deposited by standard screen printing on white paper. To ensure minimal ambient light dependence of QRsens during the real-time analysis, the smartphone application was programmed for an effective colour correction procedure based on black and white references for three standard illumination temperatures (3000, 4000 and 5000 K). Depending on the type of sensor being analysed, this integration achieved a reduction of ∼71 – 87% of QRsens's dependence on the light temperature. After the illumination colour correction, colorimetric gas sensors exhibited a detection range of 0.7–4.1%, 0.7–7.5 ppm, and 0.13–0.7 ppm for CO2, NH3 and H2S, respectively. In summary, the study presents an affordable built-in multi-sensing platform in the form of QRsens for in-situ monitoring with potential in different types of ambient air analysis applications.

Evaluation of different general V(λ) mismatch indices of photometers for LED-based light sources in general lighting applications

The general V(λ) mismatch index, , of a photometer quantifies the deviation between its determined relative spectral responsivity, , and its nominal responsivity, the spectral luminous efficiency function for photopic vision, V(λ). LED-based light sources now dominate in general lighting, displacing incandescent and fluorescent lamps. Furthermore, the calibration of photometers will very likely see the replacement of the reference CIE standard illuminant A with CIE reference spectrum L41. The article evaluates the consequences. Should we also change the definition of the general V(λ) mismatch index? Based on performance criteria, the individual indices are evaluated using various datasets with the help of statistical analyses. As a result, the authors can conclude that the current definition works very well even under changed calibration and application conditions and does not need to be changed. Other evaluated indices for a new index definition perform only slightly better in some cases, but do not generate generally better properties.

Interaction between daylighting and artificial lighting in relation to conservation and perception, according to new illumination system of Sistine Chapel

• Optimisation of perception with natural and artificial spectrum. • Daylight enhances the perceptual experience and provides it with context. • Complex lighting design measures in the Sistine Chapel. • Daylight in the Sistine Chapel does not generate profiles of conservation risk. This work provides a dual approach to the study of natural light inside the Sistine Chapel, of a purely quantitative type (measurements of absolute values) and a linked to perception aspects (spectral measurements), in the context of the great artificial lighting project implemented in 2014. The impossibility of proceeding with standard illuminance measurement instrumentation led to an alternative approach based on the fundamental relationship between illuminance and luminance on Lambertian surfaces; a graphical-experimental method of acquiring the reflection coefficients of Sistine paintings was developed to supplement in situ luminance measurements. The quantitative study was the starting point for qualitative reflections on light in order to investigate the opportunities and criticalities of daylighting: criticalities attributable to possible perceptual imbalances between different parts of the visual field and opportunities attributable to the genius loci which can be highlighted by the connection with the external light environment and its variability over the course of the day and the seasons. The concept of the naturalness of the lighting environment was investigated as a function of the variability of some quantitative variables (illuminance, luminance) and qualitative variables (emission spectrum and correlated parameters: CCT correlated colour temperature, CRI colour rendering index) related to light and variables linked to the effect of light on the colours of the frescoes (CIE coordinates, SDCM standard deviation of colour matching). The method can be applied to any confined space and produce useful results for the optimisation of exhibition spaces or, more generally, spaces characterised by the coexistence of requirements for use and conservation with natural and/or artificial light.

Integrated 4-Terminal All-Inorganic Perovskite Tandem Solar Cell with Open-Circuit Voltage Exceeding 2.1 V for Water Splitting

This work reports on Sn-Pb binary metal inorganic perovskites as narrow-bandgap absorbers for integrated 4-terminal all-inorganic perovskite tandem solar cells (TSCs). A series of Sn-Pb binary metal CsPb1–xSnxI3-yBry inorganic perovskites with tunable bandgaps ranging from 1.28 to 1.45 eV were synthesized through tuning the Sn-Pb and I-Br contents. The TSC device using a narrow-bandgap CsPb0.5Sn0.5I2.7Br0.3 bottom cell with a wide-bandgap semi-transparent CsPbI1.5Br1.5 top cell achieved a remarkable power conversion efficiency over 18% and a high open-circuit voltage (VOC) of 2.13 V, a very attractive feature for solar fuel production. To the best of our knowledge, this is the first trial of TSCs entirely made of all-inorganic perovskite absorbers, and also the record VOC achieved among double-junction TSCs based on integration of narrow- and wide-bandgap perovskite absorbers so far. Using this novel all-inorganic perovskite TSC in conjunction with a water-splitting system employing Pt/C for hydrogen evolution reaction and Fe/Ni foam for oxygen evolution reaction in alkaline electrolyte, we achieved an unprecedented solar-to-hydrogen efficiency over 13% under standard illumination test conditions.

Strain‐Stabilized CsPbI3 Perovskite via Organopolysilazane for Efficient Solar Cells with Efficiency over 19%

AbstractPrincipally, all‐inorganic perovskite crystals, such as CsPbI3, possess higher thermal stability than their organic–inorganic hybrid counterparts, like CH3NH3PbI3, due to the type of chemical bond variants. However, considering a retained strain in these stiff films, it is a challenge to stabilize CsPbI3 within the photoactive phase for photovoltaic application under ambient conditions. This article reports organopolysilazane (OPSZ) as a strain compensation layer that regulates the tense strain during the annealing process, a very attractive feature for all‐inorganic perovskite solar cells with a CsPbI3 active layer. When depositing OPSZ onto the surface of CsPbI3 film for thin‐film solar cell devices with FTO/c‐TiO2/CsPbI3/spiro‐OMeTAD/Au architecture, an efficiency of 19.12% is achieved under standard illumination test conditions. This strain compensation layer offers a viable pathway to develop efficient and stable solar cells with inorganic perovskite crystalline thin films for scale‐up and practical applications.