Morphology engineering of MAPbBr3 thin films for enhanced lighting applications

Abstract

Hybrid metal halide perovskites, specifically methylammonium lead bromide (MAPbBr3), have promising optoelectronic properties and cost-effective fabrication methods; however, challenges in achieving high photoluminescence quantum yield persist. This study explores morphology engineering of MAPbBr3 films to enhance their applicability in light-emitting diodes by sequential spin-coating methods with toluene and chloroform antisolvents, incorporating bathocuproine (BCP) as an additive. BCP is shown to improve film morphology, reducing grain size and surface roughness while increasing coverage, uniformity, and the conductivity of the layer. A novel double-layer deposition approach further enhances these properties, yielding films with complete coverage and minimized defects, without change in the microstrain. Photoluminescence measurements indicate significant trap passivation and enhanced light emission intensity and stability and a reduced threshold in the generation of amplified spontaneous emission. When integrated into PeLED devices, these engineered films demonstrate substantial performance improvements. The combination of BCP and double-layer deposition results in a luminous efficiency increase of up to 727 times compared to untreated films. This enhancement is attributed to better charge transport, reduced non-radiative recombination, and superior film morphology. This work presents a scalable and efficient method for producing high-performance MAPbBr3 films, bridging the gap between simple fabrication processes and advanced device applications.