Development of high luminous efficacy red-emitting CaAl12O19:Mn4+ phosphor using Al- and K-doped ZnO NWs/CFs

CaAl12O19:Mn4+ phosphor (CAO:Mn), which has advanced color rendering and high productivity for white light-emitting diodes (wLEDs), is an important candidate for red-emitting materials due to its large absorption band from the visible region to the deep-red region based on the d-d transitions of manganese ions. For this reason, it is widely used especially in wLEDs, and in recent years, many researchers have aimed to improve the optical properties of the aforementioned red phosphor material with the use of different dopants and additives. In this study, the observed enhancements in the photoluminescence based optical properties of sol-gel synthesized CAO:Mn phosphor were described in detail in the presence and absence of pristine zinc oxide nanowires grown on carbon fibers (ZnO NWs/CFs), Al-doped ZnO NWs/CFs (Al-ZnO NWs/CFs) and K-doped ZnO NWs/CFs (K-ZnO NWs/CFs) additives. The addition of pristine ZnO NWs/CFs and Al- and K-doped ZnO NWs/CFs to CAO:Mn phosphor in the ethyl cellulose (EC) matrix resulted in an increase in emission intensity of 74%, 81%, and 84%, respectively. Additionally, the features of the synthesized phosphor's emission/excitation spectra and decay times were examined on both the nano- and microsecond time scales. The presented material can be shown as a new candidate for improving the properties of red phosphors related to brightness, stability, and degradation times.