Magnetically Tunable Ag/CH3NH3PbBr3 Single Crystal/Ni Heterostructure for Self-Powered Photodetector

Abstract

Organometallic halide perovskites have shown immense potential for light harvesting and visible light sensing applications. Large CH3NH3PbBr3 single crystals (SC) of size 4 × 3.5 mm2 have been synthesized using a simple inverse temperature crystallization route. The X-ray diffraction spectra confirm the formation of a single crystalline phase without any impurity. UV-vis diffuse reflectance spectra show an optical band gap of ∼2.28 eV, which is suitable for visible light sensing. Thereafter, the device with architecture Ag/CH3NH3PbBr3 SC/Ni was fabricated by thermally depositing the nickel (Ni) and silver (Ag) metal on either side of the SC and was used for visible light sensing applications. The device exhibits a photocurrent of ∼3 μA·cm-2 at a forward biasing of 5 V with responsivity (R) ∼14 mA·W-1 and detectivity (D*) ∼5 × 107 Jones. Furthermore, the device is subjected to an external magnetic field (B vector) varying from 0 to 100 mT to analyze the effect of the B vector on device performance. The device shows ∼28% increment in the photocurrent at B vector of 30 mT with significantly higher R and D* of ∼37 mA·W-1 and ∼2 × 108 Jones, respectively, which is due to enhanced charge carrier transportation and lower recombination at the Ni/SC interface under the influence of external magnetic field. The present work provides a practicable strategy to tune photocurrent by an external B vector and further pave the way toward multifunctional optoelectronic devices. © 2024 American Chemical Society.