Growth methods' effect on the physical characteristics of CsPbBr3 single crystal

Abstract

This study offers an extensive exploration into approaches for cultivating CsPbBr₃ SCs using inverse temperature crystallization (ITC), with a specific focus on seed-induced (method (1)) and nucleation-mediated (method (2)) growth techniques. Our findings reveal that leveraging seed-assisted growth at lower temperatures yields noteworthy enhancements in the material's optical and electrical behaviors, outperforming the outcomes achieved through nucleation-driven growth. Concretely, through the employment of the space charge limited current (SCLC) technique, an evident contrast emerges in the trap-populated threshold voltage between the seed-facilitated crystal (SC₁) (measuring 0.309 V) and its nucleation-facilitated counterpart (SC₂) (measuring 1.513 V), consequently giving rise to discernable dissimilarities in trap density assessments. Evidence from temperature-dependent analysis of space charge limited currents substantiates these findings, revealing trap density values of 8.81 × 10⁹ cm⁻³ for SC₁, juxtaposed with 2.08 × 10¹⁰ cm⁻³ for SC₂. Additionally, the SC₁ displays a notably diminished trap energy level. Furthermore, the investigation underscores the affirmative influence of method (1) at lower temperatures on the optical and crystalline characteristics of the substance. This effect is evidenced by enhanced photoluminescence (PL) reactions and reduced lattice strain (L_s), as determined through X-ray diffraction (XRD) techniques. Moreover, the research establishes the substantial impact of this enhanced crystallization technique on the photodetector (PD) attributes of the crystal. This effect induces elevated levels of detectivity and responsivity for method (1).