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

Abstract

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.

Ionic liquid-assisted growth of high-quality methylammonium lead bromide single crystals for photodetection applications

“…The observed higher I d may primarily suggest the presence of a high defect density in the BMIB-based MAPbBr 3 SC. 38,50 However, our results reveal that the values of Z trap are lower in the BMIBbased MAPbBr 3 SC than in the reference MAPbBr 3 SC (Fig. 2e).…”

“…2b, the PL spectra exhibit a sharp peak at 542 nm (2.29 eV) with no shift in the peak position, which is consistent with the literature. 38,50 Notably, the BMIB-based MAPbBr 3 SC exhibited an enhanced PL intensity compared to the reference MAPbBr 3 SC, which indicates suppression of the nonradiative recombination in the modified SC. These results further support our findings from the XRD analysis.…”

“…It is known that the growth of SCs is generally controlled by the diffusion rate of the solute in the solution and the solute deposition rate on the crystal surface. 38 The diffusion rate in solution exponentially increases with increasing the temperature according to eqn (1):…”

“…The reduced lattice strain is beneficial for decreasing ion migration within the perovskite crystal and nonradiative recombination processes. 38,53 The trap states located within the band gap of perovskite materials play a critical role of undesirable obstacles in all photophysical applications. 31 To shed more light on the energy states and defects, photoluminescence (PL) measurements were performed on both types of SCs.…”

Surface Engineering of Methylammonium Lead Bromide Perovskite Crystals for Enhanced X-ray Detection

“…The devices for PV-SCLC measurements were prepared by depositing carbon paste on each surface of the MAPbBr 3 crystals . Then, pulsed voltages of 0.05–200 V were applied to the devices with the ON-time of 20 ms and the interval time of 120 s. Based on the log I –log V plots, we determined the onset voltage of the trap-filled limit regime ( V TFL ) as shown in Figures S8 and S9.…”