Perovskite CsCu2I3-based optoelectronic device with exceptional polarization sensitivity via point vacancy modulation

The design of polarization-sensitive, stable self-powered, and broadband photoresponse optoelectronic devices remains a big challenge. Here, the influence of vacancy defects on the electronic structure properties of CsCu2I3 has been studied by density functional theory, which reveals the feasibility of their application in the field of optoelectronic devices, and then, their photogalvanic effects have been investigated based on quantum transport simulations. The results show that the pristine CsCu2I3 and I-vacancy devices indeed generate robust photocurrents under irradiation with linearly polarized light at the near ultraviolet to the visible wavelength without bias, demonstrating the self-powered and broadband response of the devices. The extinction ratios of the pristine CsCu2I3 and I-vacancy devices were 9.84 and 33.02 at zero bias, respectively. In addition, the I-vacancy device exhibits an ultra-high extinction ratio of up to 69.7 at 0.2 V. These results demonstrate potential applications of CsCu2I3-based devices in high performance, low power, and polarization detection.