Search for: All records

Hybrid perovskite materials have emerged as excellent candidates for next-generation optoelectronic applications. Nevertheless, many vapor deposition techniques face challenges like phase segregation, thermal decomposition, and nonstoichiometric film growth. Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) addresses these challenges by eliminating thermal stability concerns for precursor materials while maintaining stoichiometry and producing high-quality film growth. Despite its advantages, scaling up RIR-MAPLE remains underexplored compared to conventional techniques. A main challenge is to ensure high throughput with precise control over film properties. RIR-MAPLE films are typically grown under an active vacuum (chamber pressure of ∼10−5 Torr). Film deposition under background gas pressure has not been investigated, leaving questions about how an inert gas environment could influence material properties. Thus, understanding film deposition in a reduced vacuum environment with background inert gas, such as nitrogen gas, is crucial to demonstrate the feasibility of higher throughput to achieve industrial scalability. This study examines the effect of nitrogen background pressure on the deposition of two-dimensional hybrid perovskite films, namely, phenethylammonium lead iodide revealing significant improvements in film crystallinity, optical properties, and defect density with increasing background pressure, thereby highlighting the potential for scaling RIR-MAPLE for the synthesis of high-performance hybrid perovskite films. 

Hybrid perovskites incorporating conjugated organic cations enable unusual charge carrier interactions among organic and inorganic structural components, but are difficult to prepare as films due to disparate component chemical/physical characteristics ( e.g. , solubility, thermal stability). Here we demonstrate that resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) mitigates these challenges, enabling facile deposition of lead-halide-based perovskite films incorporating variable-length oligothiophene cations. Density functional theory (DFT) predicts suitable organic and inorganic moieties that form quantum-well-like structures with targeted luminescence or exciton separation/quenching. RIR-MAPLE-deposited films enable confirmation of these predictions by optical measurements, which further display excited state behavior transcending traditional quantum-well models— i.e. , with appropriate selection of specially synthesized organic/inorganic moieties, intercomponent carrier transfer efficiently converts excitons from singlet to triplet states in organics for which intersystem crossing cannot ordinarily compete with recombination. These observations demonstrate the uniquely versatile excited-state behavior in hybrid perovskite quantum wells, and the value of integrating DFT, organic synthesis, RIR-MAPLE and spectroscopy for screening/preparing rationally devised complex structures.