Oriented surface arrays on perovskite single-crystal thin films for enhanced polarization sensing

Since polarized light can carry additional information to enhance target and environment identification, detection of polarized light has been widely used in complex environments and conditions. Generally, anisotropic arrayed gratings or structures are required to capture polarized signals, and these additional structures inevitably increase the size of the device and limit its application. Given this, using spontaneously grown anisotropic structures to enhance polarization identification has become an important direction to achieve miniaturized polarization detection. Organic-inorganic halide perovskites have been widely used in optoelectronic devices due to their excellent extinction coefficient and photogenerated carrier transport properties. Meanwhile, due to its simple solution preparation process, micro-region morphology modulation of perovskites can be realized using template-confined growth. In this work, ordered surface channels are constructed on MAPbBr₃ single-crystal thins film by template-confined growth. PDMS templates are utilized to transfer the CD- and DVD-ROM grating pattern and act as the templates to confine the single-crystal growth. By optimizing the imprinting parameters, channel arrays with spacing of 1450 nm and 760 nm are constructed on the surface of single crystals. Further, polarized photodetectors based on MAPbBr₃ single-crystal thin films are constructed with a high on/off ratio of 450 and a specific detectivity of 5 × 10⁹ Jones. The patterned detectors with intervals of 1450 nm and 760 nm exhibit enhanced polarization sensitivities of 1.72 and 1.83, respectively.