Controlled Conversion of As-Cast Perovskite Thin Film Using Antisolvent Bath

Student's name: Adriana Lara Home Institution: North Carolina State University NNCI Site: RTNN @ NCSU REU Principal Investigator : Dr. Aram Amassian - Department of Materials Science and Engineering, NCSU REU Mentor: Dr. Boyu Guo Abstract: Hybrid perovskite semiconductors (SCs) have received significant attention for their potential in photovoltaic applications. While synthesizing standalone SCs is straightforward, the technological significance lies in the ability to directly grow SCs on foreign substrates. However, this poses significant challenges due to the prevalence of heterogeneous nucleation. This study delved into antisolvent techniques to gain insights into the factors influencing the quality of thin films in ambient temperatures. FA0.9Cs0.1Pb(I0.85Br0.15) was chosen as the precursor, and we used three distinct antisolvent methods—drip, bath, and combined drip-bath—with chlorobenzene, diethyl ether, and toluene as antisolvents. The films are spin-coated in a glass substrate under a UV-Vis spectrophotometer to observe the conversion process of the films throughout time. This study contributes to the fundamental understanding of antisolvent techniques in perovskite semiconductor processing, offering insights into optimizing film morphology. Hybrid perovskite semiconductors (SCs) have received significant attention for their potential in photovoltaic applications. While synthesizing standalone SCs is straightforward, their technological significance lies in the ability to directly grow SCs on foreign substrates. However, this poses significant challenges due to the prevalence of heterogeneous nucleation. Previous studies suggest that the antisolvent drip method may not reach complete crystallization prior to annealing. Conversely, the antisolvent bath method has demonstrated more uniform and complete crystallization before annealing. Incomplete crystallization has been shown to increase stress in the substrate, which is correlated with lower quality films. This study delves into different antisolvent techniques to gain insight into the factors influencing the quality of thin films in ambient temperatures. FA0.9Cs0.1Pb(I0.85Br0.15) was the chosen precursor which we used with three distinct antisolvent methods—drip, bath, and combined drip-bath—with chlorobenzene, diethyl ether, and toluene. The films are spin-coated in a glass substrate under a UV-Vis spectrophotometer to observe the conversion process and crystal growth of the films throughout time. This study contributes to the fundamental understanding of antisolvent techniques in perovskite semiconductor processing, offering insights into optimizing film morphology and crystallography.