Reduced defect density in crystalline halide perovskite films via methylamine treatment for the application in photodetectors

Autor: Emilia R. Schütz, Azhar Fakharuddin, Yenal Yalcinkaya, Efrain Ochoa-Martinez, Shanti Bijani, Abd. Rashid bin Mohd Yusoff, Maria Vasilopoulou, Tobias Seewald, Ullrich Steiner, Stefan A. L. Weber, Lukas Schmidt-Mende
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: APL Materials, Vol 10, Iss 8, Pp 081110-081110-11 (2022)
Druh dokumentu: article
ISSN: 2166-532X
DOI: 10.1063/5.0093333
Popis: Considerable efforts have been devoted to optimizing and controlling the morphology and electronic properties of lead halide perovskites. The defect density of a perovskite layer strongly depends on the processing conditions. Consequently, the fabrication process of high-quality films is often complex, and reproducibility is a challenge. In this work, we present a methylamine gas-based method to recrystallize perovskite layers of any given quality in a controlled way, leading to millimeter-sized domains. Crystallinity significantly increases upon methylamine treatment, and crystal growth follows a preferred orientation. Photoluminescence- and space-charge limited current measurements show that the trap density halves after recrystallization. Conductive atomic force microscopy measurements show a higher surface conductivity and an improved spatial homogeneity after methylamine treatment. When applied in photodetectors, the improved film quality of the recrystallized films leads to increased detectivities of ≈4 × 1011 Jones compared to 3 × 109 Jones of a reference device. The response time falls from 0.1 to 10−5 s upon methylamine treatment. Our work, thus, presents a promising route to fabricating reproducible, high-quality perovskite films through well-controllable recrystallization.
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