3results about How to "Reduce surface defect density" patented technology

This invention discloses a perovskite thin film with surface defect passivation and a method for passivating surface defects in a perovskite thin film. The method includes the following steps: Step 1, taking 0.430~0.530 g PbI2, 0.170~0.190 g FAI, 0.075~0.085 g PbBr2, 0.015~0.025 g MABr and 0.015~0.020 g CsI, and dispersing them while stirring in a mixed solvent of 800 mL N,N-dimethylformamide and 200 mL dimethyl sulfoxide to prepare a perovskite precursor solution; Step 2, adding LiF to an organic solvent to prepare a solution with a concentration of 0.05~35 mmol L. ‑1 Additive solution A; Step 3: Uniformly drop-coat the perovskite precursor solution onto the FTO conductive glass substrate, and turn on the spin coater to coat it into a perovskite thin film; Step 4: In the last 10 seconds before the spin coater stops rotating, rapidly drop additive solution A onto the surface of the perovskite thin film, anneal it under an argon atmosphere, and after drying, obtain a perovskite thin film with passivated surface defects, which improves the solar energy utilization rate of the perovskite thin film, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

This invention discloses a differential centrifugation method for separating α-Al₂O₃ nanoparticles based on morphological response differences, comprising the following steps: S1: Dispersing α-Al₂O₃ nanoparticles at a concentration of 0.55 wt% in anhydrous ethanol, and continuously dispersing the particles using an ultrasonic device; S2: Centrifuging the resulting suspension at 10,000–15,000 rpm, discarding the lower precipitate, and retaining the supernatant; S3: Dispersing the supernatant again using ultrasonication under the same conditions as in step S1; S4: Centrifuging the dispersed system at 4,000–7,000 rpm at a medium speed, and collecting the lower precipitate; S5: Repeating the combined process of steps S2–S4 2–3 times, merging all precipitates obtained in the medium-speed centrifugation stage, and obtaining the target α-Al₂O₃ nanoparticles after drying. The particles obtained by this method exhibit higher polishing rates, lower surface roughness, and lower defect density in CMP, which improves density and grain uniformity in ceramic sintering. At the same time, the method has a clear process, adjustable parameters, and strong equipment versatility, and has significant potential for industrial scale-up and engineering applications.

This invention discloses a PS carrier tape with an intermediate barrier structure and its preparation method, belonging to the field of electronic packaging materials technology. The PS carrier tape includes an upper surface layer, an intermediate layer, and a lower surface layer. The upper and lower surface layers are antistatic black material layers containing small molecule additives, and the intermediate layer is a modified polystyrene layer containing dispersed nanosheet barrier materials and nucleating agents. This invention introduces nanosheet barrier materials and nucleating agents into the intermediate layer, utilizing their synergistic effect to form a barrier effect and dense crystalline regions, effectively inhibiting the migration of small molecule additives from the upper and lower surface layers to the die opening, thus reducing die opening material accumulation at the source. Compared with existing technologies, this invention significantly reduces the surface defect density of the carrier tape and the quality of die opening material accumulation, while maintaining or improving tensile strength and antistatic properties, greatly extending the downtime cleaning cycle, improving production efficiency and product yield, and is suitable for surface mount packaging of high-end electronic components.