Highly Luminescent and Stable Si-Based CsPbBr₃ Quantum Dot Thin Films Prepared by Glow Discharge Plasma with Real-Time and In Situ Diagnosis

Although all-inorganic perovskite quantum dots (QDs) have outstanding optoelectronic properties, they tend to have poor stability in air and water, at high temperatures, and under light irradiation. Herein, a glow discharge plasma process incorporating real-time and in situ diagnosis is designed for efficient encapsulation to improve the stability of CsPbBr₃ QD films. An ammonia/silane plasma which has less destructive effects on CsPbBr₃ QDs is used in plasma-enhanced chemical vapor deposition to produce a-SiN_x:H on the CsPbBr₃ QDs. The a-SiN_x:H encapsulating layers endow CsPbBr₃ QDs with long-term stability during exposure to air, at a high temperature (205 °C), and in water. In contrast to severe degradation of pure CsPbBr₃ QDs under UV illumination, the CsPbBr₃ QDs/a-SiN_x:H films show more than 5-folds increase in photoluminescence intensity after UV illumination for 80 d and long-term stability is observed after UV illumination for 140 d. The plasma treatment not only stabilizes CsPbBr₃ QDs, but enhances photoluminescence efficiency by combining with illumination as well. The nanocomposite films assembled into commercial InGaN chips feature strong cold white emission. Our results reveal a practical way to design and fabricate highly luminescent as well as stable Si-based CsPbBr₃ QD films for future development of optoelectronic devices.