Impact of Low-Temperature Seed-Assisted Growth on the Structural and Optoelectronic Properties of MAPbBr3 Single Crystals

This work presents a detailed investigation of seed and nucleation-assisted growth methods for the inverse temperature crystallization (ITC) of methylammonium lead bromide single crystals. We have demonstrated that low-temperature seed-assisted growth results in significant improvements in both optical and electrical responses of the material compared to the nucleation-assisted growth. Specifically, the space charge limited current method reveals a reduced trap-filled limit voltage of 0.287 V for the seed-assisted crystal compared to 0.923 V for the nucleation-assisted one, resulting in differences in trap density values. Temperature dependence space charge limited current analysis confirms these results, showing trap densities of 9.47 × 109 cm–3 for seeded crystal growth compared to 3.21 × 1010 cm–3 for the nucleation-assisted growth, as well as a lower trap energy level for the seeded crystal. The study also highlights that the low-temperature seed-assisted growth has a positive impact on the optical and crystalline properties of the material with improved photoluminescence response and a lower lattice strain determined by X-ray diffraction. Furthermore, the study demonstrates that this improved crystallization method has a significant influence on the photodetector properties of the crystal, leading to higher detectivity and responsivity values for the seed-assisted approach.