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* similar to 10(14) 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, Id 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 Id 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.