A comprehensive review on dark current in perovskite photodetectors: Origin, drawbacks, and reducing strategies

Perovskite photodetectors (PPDs) are emerging as one of the revolutionary optoelectronic device that explore the benefits of photoactive perovskite materials. Recently, PPDs have been demonstrated to detect wide/narrow spectra with strong responsivity and excellent detectivity (D* ∼ 10¹⁴ Jones). However, dark current (I_d) is an important parameter for PDs which is typically high for PPDs and limits the device performance. Therefore, it is critical to comprehend the origin of I_d and reducing methods before applying them to real-world applications such as imaging, sensors, surveillance cameras, etc. A smaller I_d is imperative for the detection of low-intensity incident photons, which directly affects the I_on/I_off, linear dynamic range (LDR), and responsivity in PDs. Generally, I_d arises due to uncontrolled charge carrier injection, traps, and leakage paths in PPDs. Although, control over the I_d leads to optimize the other important parameters of PPDs like noise current and responsivity. Thus, the origin and strategies to minimize I_d have been summarized by exploring the morphological transformation of the photoactive perovskite layers, choice of the transport layers, and device architectures. Moreover, the future perspective and challenges are highlighted that need to be addressed before commercializing PPD-based technology.