  Following the recent surge of interest in n-doped strontium titanate as a
possible blue light emitter, a time-resolved photoluminescence analysis was
performed on nominally pure, Nb-doped and oxygen-deficient single-crystal
SrTiO3 samples. The doping-effects on both the electronic states involved in
the transition and the decay mechanism are respectively analyzed by comparing
the spectral and dynamic features and the yields of the emission. Our
time-resolved analysis, besides shedding some light on the basic recombination
mechanisms acting in these materials, sets the intrinsic bandwidth limit of the
proposed blue light emitting optoelectronic devices made of Ti-based
perovskites heterostructures in the GHz range.
