A Comparison on Ce3+ Luminescence in Borate Glass and YAG Ceramic: Understanding the Role of Host’s Characteristics

The inefficient luminescence performance of Ce3+ activated glasses is primarily responsible for their commercial failure compared to the Ce3+ activated crystalline materials that are widely used as phosphors and scintillators. We observed that this behavior is explicitly related to the intrinsic characteristics of the host material. Here, we present a systematic study on Ce3+ luminescence in amorphous borate glass and make a comparison with the well-known polycrystalline Y3Al5O12:Ce3+ (YAG:Ce) phosphor. In borate glass, Ce3+ exhibits blue luminescence with quantum yield (QY) of about 42%, whereas the QY is more than 85% in YAG:Ce ceramic that exhibits yellow luminescence. This typical behavior has been discussed in terms of the site rigidity of dopant ions in the glassy and crystalline hosts, and its influence on the Ce3+ 5dj states' crystal field splitting, Stokes shift, and the centroid shift, as well as the probability of thermal ionization, host's intrinsic absorption, and the influence of Ce4+ impurity presence in the respective host materials. This study gives a quantitative understanding of host's contribution on dopant's luminescence properties and thereby provides an optimization guideline, which is highly demanding for the design of novel luminescent materials.