Water-Soluble Polymeric Interfacial Material for Planar Perovskite Solar Cells

Quantum Dots as a Potential Multifunctional Material for the Enhancement of Clinical Diagnosis Strategies and Cancer Treatments

Quantum dots (QDs) represent a class of nanoscale wide bandgap semiconductors, and are primarily composed of metals, lipids, or polymers. Their unique electronic and optical properties, which stem from their wide bandgap characteristics, offer significant advantages for early cancer detection and treatment. Metal QDs have already demonstrated therapeutic potential in early tumor imaging and therapy. However, biological toxicity has led to the development of various non-functionalized QDs, such as carbon QDs (CQDs), graphene QDs (GQDs), black phosphorus QDs (BPQDs) and perovskite quantum dots (PQDs). To meet the diverse needs of clinical cancer treatment, functionalized QDs with an array of modifications (lipid, protein, organic, and inorganic) have been further developed. These advancements combine the unique material properties of QDs with the targeted capabilities of biological therapy to effectively kill tumors through photodynamic therapy, chemotherapy, immunotherapy, and other means. In addition to tumor-specific therapy, the fluorescence quantum yield of QDs has gradually increased with technological progress, enabling their significant application in both in vivo and in vitro imaging. This review delves into the role of QDs in the development and improvement of clinical cancer treatments, emphasizing their wide bandgap semiconductor properties.

Flexible automated system for laser modified layer by layer assembly

An open-source automated system for laser modified layer by layer assembly is described. This flexible system, the first designed to be used with this process, can be used to fabricate a range of laser patterned, layer by layer thin films. The Arduino microcontroller-based system features a stepper motor-controlled turntable that holds solutions and water rinses for dipping. The substrate can be moved vertically to be dipped into each of the solutions throughout the process. A semiconductor laser is used to modify the thickness of the thin film during the chosen dipping cycles. Several aspects of the robotic system are easily controlled via software, including the average laser power, irradiation time, horizontal laser position, and vertical substrate position. The system is fully automated and, once started, does not require any user interaction. To demonstrate the capability of the automated system for patterning, electrochromic thin film devices using 50-bilayer laser patterned films using the polymers poly(allylamine hydrochloride) and sodium poly[2-(3-thienyl)-ethoxy-4-butylsulfonate] are presented. One device is patterned with the shape of a large "C," created by irradiating the sample (55 mW average power, 405 nm) while the substrate was moved vertically up and down or the laser was moved horizontally. The laser irradiates the sample during only the dipping in the polycation polymer solution. A second electrochromic thin film device is based on a sample with five parallel laser patterned lines, where each line is fabricated with different average laser powers and, hence, different thicknesses. The thicknesses of the lines vary by about 30 nm.

Atomic layer deposition of SnO2 using hydrogen peroxide improves the efficiency and stability of perovskite solar cells

Low-temperature processed SnO₂ is a promising electron transporting layer in perovskite solar cells (PSCs) due to its optoelectronic advantage. Atomic layer deposition (ALD) is suitable for forming a conformal SnO₂ layer on a high-haze substrate. However, oxygen vacancy formed by the conventional ALD process using H₂O might have a detrimental effect on the efficiency and stability of PSCs. Here, we report on the photovoltaic performance and stability of PSCs based on the ALD-SnO₂ layer with low oxygen vacancies fabricated via H₂O₂. Compared to the ALD-SnO₂ layer formed using H₂O vapors, the ALD-SnO₂ layer prepared via H₂O₂ shows better electron extraction due to a reduced oxygen vacancy associated with the highly oxidizing nature of H₂O₂. As a result, the power conversion efficiency (PCE) is enhanced from 21.42% for H₂O to 22.34% for H₂O₂ mainly due to an enhanced open-circuit voltage. Operational stability is simultaneously improved, where 89.3% of the initial PCE is maintained after 1000 h under an ambient condition for the H₂O₂-derived ALD SnO₂ as compared to the control device maintaining 72.5% of the initial PCE.