Lawrence Berkeley National Laboratory

We have investigated the occurrence of the sometimes observed grain boundaries, as initial seed is extended to form line in laser-fabricated single-crystal architecture in glass (SCAG). In particular, for Sb2S3 SCAG in Sb-S-I glass as a model system, grain boundaries are formed during the transition from laser-written initial seed dot to crystal line. Such grain boundaries during the growth of Sb2S3 crystals occur in 16SbI3–84Sb2S3 glass, whereas they are absent in Sb2S3 glass. We correlate this difference in tendency to form multiple grains with the relative glass forming ability i.e. the dynamics of nucleation and crystal growth as determined by differential scanning calorimetry (DSC). On the basis of this understanding, methods to minimize the appearance of grain boundaries in the transition region are suggested.