Effect of a-SiC(x)N(y):H Encapsulation on the Stability and Photoluminescence Property of CsPbBr(3) Quantum Dots

The effect of a-SiC(x)N(y):H encapsulation layers, which are prepared using the very-high-frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) technique with SiH(4), CH(4), and NH(3) as the precursors, on the stability and photoluminescence of CsPbBr(3) quantum dots (QDs) were investigated in this study. The results show that a-SiCxNy:H encapsulation layers containing a high N content of approximately 50% cause severe PL degradation of CsPbBr(3) QDs. However, by reducing the N content in the a-SiCxNy:H layer, the PL degradation of CsPbBr(3) QDs can be significantly minimized. As the N content decreases from around 50% to 26%, the dominant phase in the a-SiCxNy:H layer changes from SiNx to SiCxNy. This transition preserves the inherent PL characteristics of CsPbBr(3) QDs, while also providing them with long-term stability when exposed to air, high temperatures (205 °C), and UV illumination for over 600 days. This method provided an effective and practical approach to enhance the stability and PL characteristics of CsPbBr(3) QD thin films, thus holding potential for future developments in optoelectronic devices.