Stable Luminescent CsPbI3 Quantum Dots Passivated by (3-Aminopropyl)triethoxysilane.

Perovskite nanomaterials have been fascinating for commercial applications and fundamental research owing to their excellent optical properties and satisfactory processability. They are expected to be alternative downconversion materials in phosphor-converted LEDs for lighting or display technology. However, owing to their low formation energy and large specific surface area, perovskite nanomaterials are sensitive to environmental stress like humidity, heat, etc. In this paper, cubic CsPbI3 quantum dots (QDs) with improved stability are synthesized using (3-aminopropyl)triethoxysilane (APTES). These luminescent CsPbI3 QDs passivated by APTES not only show excellent stability when stored in hexane but also possess outstanding steadiness for lattice structure when prepared as a thin film in open air. They do not decompose immediately in the water. Such excellent stability is attributed to the hindrance from hydrolysis of APTES, which forms an analogous core-shell structure to protect the "core" CsPbI3 QDs. Furthermore, an additional iodine source is added to enhance their emissionm and CsPbI3QDs with a PLQY of 84% are synthesized.

Enhanced Performance and Stability of Perovskite Solar Cells Through Surface Modification with Benzocaine Hydrochloride.

Current development of inverted p-i-n perovskite solar cells (PSCs), with nickel oxide as the hole transport layer, is progressing toward lower net costs, higher efficiencies, and superior stabilities. Unfortunately, the high density of defect-based traps on the surface of perovskite films significantly limits the photoelectric conversion efficiency and operational stability of perovskite solar cells. Finding cost-effective interface modifiers is crucial for the further commercial development of p-i-n PSCs. In the present work, we report a passivation strategy using a multifunctional molecule, benzocaine hydrochloride (BHC), which is shown to reduce defect density and enhance the photovoltaic performance and stability of the resultant p-i-n PSCs. It has been revealed that BHC strongly interacts with perovskite precursor components and triggers the evolution of the perovskite absorber film morphology and enables improved surface energy level alignment, thus promoting charge carrier transport and extraction. These properties are beneficial for improving open-circuit voltage (VOC) and fill factor (FF). Our results show that the photoelectric conversion efficiency (PCE) of p-i-n PSCs with nickel oxide as the hole transport layer increased from an initial 20.0% to 22.1% after being passivated with BHC, and these passivated devices also exhibited improved stability. DFT calculations reveal the unusual ability of the BHC passivant to improve band alignment while also preventing the accumulation of holes at the interface. In this work, the advantages of BHC passivation are demonstrated by linking theoretical calculations with optical and electrical characterizations.