Daniel Prochowicz

Lead-free Cs2AgBiBr6 double perovskite single crystals (SCs) have emerged as promising candidate for photodetection application due to their long carrier lifetimes, high structural stability, and low toxicity. However, their relatively wide band gap (∼2.1 eV) fundamentally limits their long-wavelength photodetection, restricting broader optoelectronic use. In this work, deep-red photodetection of Cs2AgBiBr6 SCs was achieved through the application of a controlled thermal treatment process. Specifically, the as-fabricated Cs2AgBiBr6 SC-based photoconductor exhibits great sensitivity to deep-red illumination (720 nm) at 343 K and 4 V bias with a responsivity of up to 0.70 A W–1 and a specific detectivity of 3.75 × 1011 Jones. This capability was attributed to the thermally activated sub-bandgap absorption pathways arising from deep defect states. The presence of such absorption was confirmed by photoacoustic spectroscopy. Finally, the stability evolution of photodetection performance to the applied thermal stress over time was investigated.

Colloidal nanocrystals (NCs) represent a transformative class of materials for next‐generation optoelectronic devices, including photodetectors (PDs), photovoltaics (PVs), catalysis, and light‐emitting diodes (LEDs). Historically, research in this field has been dominated by toxic heavy‐metal‐based systems (Cd, Pb, Hg), but it is now undergoing a critical shift toward sustainability, driven by health concerns and RoHS regulations. This review provides a comprehensive overview of heavy‐metal‐free (HMF) chalcogenide NCs, including binary, ternary, and multinary systems. We analyze the fundamental principles governing their performance, specifically size‐dependent quantum confinement and compositional tuning that allow these “green” alternatives to achieve photoluminescence quantum yields exceeding 70%–90% and power conversion efficiencies of 8%–12%. This review further explores the unique structure‐property relationships of HMF chalcogenide NCs, highlighting their superior biocompatibility, low toxicity profiles, and defect‐tolerant electronic structures. Diverse applications are evaluated, ranging from broadband infrared photodetection to high‐purity color emission for QLEDs. Special emphasis is placed on the challenges of surface engineering and ligand exchange, focusing on the transition from time‐consuming layer‐by‐layer processing to efficient one‐step solution‐phase strategies. Finally, future research directions are outlined, including mitigation of ions in HMF chalcogenide NCs and development of self‐powered sensing platforms for the Internet of Things (IoT) and wearable electronics.

Perovskite solar cells (PSCs) have rapidly approached the performance limits of established photovoltaic technologies, yet their long‐term operational stability remains a persistent bottleneck for real‐world deployment. By introducing 1‐butyl‐4‐methylpyridinium tetrafluoroborate (BMPyBF ₄ ) as a molecular additive, the perovskite interface demonstrated simultaneous defect passivation and energetic reconfiguration, leading to markedly improved charge transport. At an optimal concentration (0.5 mmol%), BMPyBF ₄ ‐incorporated PSCs achieve a remarkable open‐circuit voltage ( V _OC ) of 1.18 V, a short‐circuit current density ( J _SC ) of 24.37 mA/cm ² , a fill factor (FF) of 82%, and a champion power conversion efficiency (PCE) of 23.6%, significantly outperforming the control device (21.7%) and a state‐of‐the‐art imidazolium‐based IL (BMIMBF ₄ )‐doped device (22.6%). Transient absorption spectroscopy (TAS) measurements further corroborate these results by revealing modified carrier dynamics and suppressed recombination in BMPyBF ₄ ‐treated films, consistent with improved interfacial charge dynamics. Furthermore, stability assessments demonstrate a profound impact of BMPyBF ₄ ; while the reference device loses 33% of its initial efficiency after 500 h of operation, BMPyBF ₄ ‐modified PSCs retain 99% of their initial performance even after 1000 h. Similar improvements are observed under thermal stress at 65°C. These findings position pyridinium ILs as multifunctional interfacial regulators capable of simultaneously controlling defect chemistry, charge transport, and device stability.

Hybrid lead halide perovskitoids with extended 3D connection modes have attracted a lot of attention for optoelectronic and photodetection applications, but up to now, only one example comprising divalent and monovalent cations is known, i.e., MPDA2FAPb4Br13 (MPDA = N-methylpropanediammonium, FA = formamidinium). We expand the family of mixed-cation 3D perovskitoids by introducing three analogues comprising methylammonium (MA), ethylammonium (EA), and dimethylammonium (DMA) cations in small perovskite voids. X-ray diffraction and optical studies show that these compounds adopt a monoclinic system with P2/m symmetry and are examples of 3D perovskitoids exhibiting both narrowband and broadband photoluminescence (PL) and pronounced thermochromism. Analysis of the structural and optical data revealed that the intensity of the broadband PL increases with increasing intraoctahedral distortion, mainly of the corner-sharing PbBr6octahedra. Moreover, using MPDA2MAPb4Br13, we fabricated a single-crystal-based photodetector that performs at a much lower bias voltage (0.5 V) compared to photodetectors based on other 3D perovskitoids (10 V). In addition, the device’s photocurrent remains unchanged after multiple cycles of operation under 448 nm illumination, indicating excellent stability and reliability of the photodetector. All these results not only show that a relaxed tolerance factor applies to 3D perovskitoids, paving the way for expanded structural versatility and optoelectronic tunability in this family of compounds, but also inspire further exploration of these compounds as light-emitting and photodetection materials.

The colloidal synthesis of Ag‐based lead‐free double perovskite nanocrystals (NCs) involves Ag ⁺ ‐reduction mediated pathways, however, the role of Ag redox chemistry in lattice formation remains poorly understood. Here, we elucidate the crystallization‐driven redox processes that govern the formation of Cs ₂ AgBiBr ₆ NCs. An alternative synthesis has been proposed by carefully studying the effect of reaction temperature behind the in‐situ Ag‐reduction aided from Ag‐oleate complex decomposition at >175 °C, followed by its oxidation mediated by the addition of exclusively used halide precursor, oleylammonium bromide (OLAmBr). The halide precursor participates in the oxidation of in‐situ formed Ag ⁰ followed by the crystallization of Cs ₂ AgBiBr ₆ NCs. This work establishes halide‐mediated oxidative etching as a key step in the crystallization of lead‐free double perovskite NCs.

The rapid evolution of modern electronic devices has significantly increased the demand of energy storage systems that are lightweight, durable, and capable of delivering both high energy and power densities. Among emerging electrode materials, biomass‐derived activated carbon (BDAC) has gained significant attention as a sustainable and scalable alternative to conventional carbon materials for supercapacitors (SCs). This interest stems from its abundant availability, low cost, tunable porous structure, excellent electrochemical performance, and eco‐friendly production approach. This review systematically summarizes recent advances in BDAC synthesis, structural engineering, composite fabrication, electrolyte selection, and device architecture for SC applications. Particular emphasis is placed on composite engineering strategies integrating metal oxides, conducting polymers (CPs), and MXenes to enhance pseudocapacitive contributions and improve overall energy density. The influence of electrolyte systems including aqueous, organic, and solid‐state configurations on voltage window expansion, ionic transport, and device stability is critically examined. Recent progress in flexible and wearable SC architectures is also highlighted. Finally, key challenges related to scalability, reproducibility, green processing, and long‐term stability are discussed, along with future directions toward industrial‐scale manufacturing of sustainable carbon electrodes. Overall, BDAC‐based SCs represent a promising pathway toward next‐generation eco‐friendly energy storage technologies for portable and wearable electronic devices.

Analysis of adduct formation in isostructural model organoaluminum and organogallium carboxylates with various neutral N , N ′-ditopic Lewis bases reveals design rules that support the development of main-group-derived coordination polymers.

We present a novel approach to enhance the efficiency and stability of inorganic CsPbI ₂ Br based perovskite solar cells (PSCs) through the incorporation of a solvated palladium (Pd) complex, PdBr ₂ (PhCN) ₂ , into perovskite precursor inks (PhCN = benzonitrile). This modification not only stabilizes the α‐phase of CsPbI ₂ Br perovskite owing to Pd ²⁺ ions, which were found to be incorporated into the perovskite structure at the B‐site, but also effectively improves the perovskite film morphology through the removal of benzonitrile molecules during annealing. Further systematic study reveals that the addition of PdBr ₂ (PhCN) ₂ results in a better matched energy‐level alignment and reduced charge carrier recombination compared to the unmodified material. As a result, the optimized device enables an efficiency of 16.4% with an open‐circuit voltage ( V _OC ) of 1.27 V, which outperforms the control device (14.1%, 1.19 V). The device with PdBr ₂ (PhCN) ₂ shows substantially enhanced environmental and operational stabilities, retaining ≈75% and 90% of their initial PCEs after 500 h aging, respectively. This study demonstrates the potential of B‐site engineering via solvated precursors as an effective route toward stable and efficient inorganic perovskite photovoltaics.

Perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies (PCEs) and cost‐effective fabrication processes. However, defects in the bulk and interfaces of perovskite materials, as well as Li ⁺ migration (especially in n–i–p regular architecture), which are used to enhance the conductivity and hole mobility of spiro‐OMeTAD, can significantly impact device performance and stability. Herein, we report a rationally designed meso ‐crowned porphyrin derivative ( [12]‐C‐4POR ) featuring dual macrocyclic binding sites, i.e., a porphyrin core for undercoordinated Pb ²⁺ and a crown ether unit selective for Li ⁺ to suppress surface defects and mitigate lithium‐ion migration simultaneously. The incorporation of [12]‐C‐4POR into perovskite films significantly reduced the trap‐state density and suppressed non‐radiative recombination, leading to improved charge‐carrier dynamics. Devices treated with [12]‐C‐4POR delivered a champion PCE of 23.14%, surpassing the control device (21.6%), along with enhanced open‐circuit voltage (V _OC ) and fill factor (FF). More importantly, the passivated devices retained ∼95% of their initial PCE after 800 h of continuous operation, compared to ∼55% for the control. This study demonstrates a dual‐site host–guest passivation strategy as an effective route to improve both efficiency and operational stability of PSCs.

The global deployment of photovoltaic (PV) systems is projected to exceed 4.5 TW by 2050, with cumulative end‐of‐life (EoL) module waste surpassing 60 million tonnes. Effective recycling of crystalline silicon (c‐Si) modules is therefore critical to ensure the sustainability of solar energy. This review describes the progress across recycling routes, including mechanical, thermal, chemical, and emerging hybrid approaches, while evaluating their techno‐economic and policy implications. Mechanical recycling, currently the most commercialized method, achieves recovery rates of 80%–90% for bulk glass and aluminum but results in contamination losses of silver and high‐purity silicon. Thermal processes such as pyrolysis and incineration recover silicon with purities up to 99.9999% and silver with recovery rates above 90%, although they require temperatures exceeding 500°C and incur significant energy costs. Chemical dissolution offers the highest selectivity, with silver recovery above 95% and near‐complete ethylene vinyl acetate (EVA) removal, but the use of toxic solvents and long reaction cycles limit industrial adoption. Hybrid strategies combining mechanical pretreatment with chemical or thermal steps have demonstrated material recovery exceeding EU WEEE Directive targets (85% recovery, 80% reuse). Economic analyses suggest potential revenues of $11–12 per module, driven largely by silver and glass recovery, but profitability remains sensitive to logistics and commodity price fluctuations. Policy frameworks such as extended producer responsibility (EPR) in the EU, mandatory recycling programs in Washington State, and emerging circular economy laws in China illustrate the critical role of governance in scaling recycling. The review concludes that advancing eco‐friendly solvents, low‐energy thermal designs, and harmonized global policies will be pivotal to achieving circularity in PV systems.