Unified benchmarking and characterization protocol for nanomaterial-based heterogeneous photodetector technologies

Over the last few years, there has been a rapid growth towards demonstrating highly sensitive, fast photodetectors using photoactive nano-materials. As with any other developing and highly inter-disciplinary field, the existing reports exhibit a large spread in the data due to less optimized materials and non-standardized characterization protocols. This calls for a streamlined performance benchmarking requirement to accelerate technological adoption of the promising candidates. The goal of this paper is four-fold: (i) to address the key challenges to perform such benchmarking exercise; (ii) to elucidate the right figures of merit to look for, and in particular, to demonstrate that noise-equivalent-power ($N\!E\!P$) is a more reliable sensitivity metric than other commonly used ones, such as responsivity ($R$) and specific detectivity ($D^*$); (iii) to propose $N\!E\!P$ versus frequency of operation ($f$) as a single, unified benchmarking chart that could be used for apple-to-apple comparison among heterogeneous detector technologies; and (iv) to propose a simple, yet streamlined characterization protocol that can be followed while reporting photodetector performance.