Development of Organic Semiconductor Photodetectors: From Mechanism to Applications

Abstract

Photodetectors that convert a light signal into an electrical signal have wide applications in light signal detection. As an emerging candidate for next‐generation light sensing, organic photodetectors compensate well for the shortages of the traditional inorganic photodetectors in terms of ease of processing, compatibility with flexible substrates, tunable absorption characteristics, low‐cost manufacturing, and being lightweight. Currently, regular improvements in organic photodetectors are made with respect to their important figure‐of‐merit performances, which have caught up to or even surpassed the performances of inorganic Si and Ge‐based photodetectors. Importantly, the spectral response of organic photodetectors covers a wide range of wavelengths, from the ultraviolet to near‐infrared regions, with low‐band‐gap organic semiconductors as the active medium. In this paper, the working mechanism and recent advances in organic semiconductor photodetectors are comprehensively reviewed and the challenges in the field, mainly focusing on the performance of organic photodetectors, studies oriented toward applications, and the expectations of organic semiconductor photodetectors in the future, are disclosed.

Low‐dimensional nanomaterial/Si heterostructure‐based photodetectors

“…The responsivity ( R ) is defined as the ratio of the generated photocurrent to optical power and is calculated by the following equation: where I p is the photocurrent, I d is the dark current, P is the incident power density, and S is the active area. R depends on the wavelength of the incident light.…”

“…The responsivity (R) is defined as the ratio of the generated photocurrent to optical power and is calculated by the following equation 25 :…”

Directed self-assembly of viologen-based 2D semiconductors with intrinsic UV–SWIR photoresponse after photo/thermo activation

“…As reported, some singlecomponent inorganic photoelectronic semiconductors showed strikingly wide detection ranges, for example, the photoresponse range of SnTe covers 254-4650 nm 13 . However, practical application of them is still greatly limited by material rigidity, as well as complex and expensive manufacturing processes 14,15 . Organic-based photoelectronic semiconductors are characteristic of flexibility and facile preparation, but the observed up limit for photoresponse is about 1800 nm 10,12,[15][16][17][18] .…”

“…However, practical application of them is still greatly limited by material rigidity, as well as complex and expensive manufacturing processes 14,15 . Organic-based photoelectronic semiconductors are characteristic of flexibility and facile preparation, but the observed up limit for photoresponse is about 1800 nm 10,12,[15][16][17][18] . It is still of importance to develop effective and general design methods for single-component organic-based semiconductors with intrinsic photoresponse in the entire UV-SWIR range.…”

Recent developments in flexible photodetectors based on metal halide perovskite

“…Currently, all sorts of active materials including low‐dimensional inorganic nanostructures, perovskite materials, organic semiconductors and two‐dimensional (2D) materials etc. have been extensively studied for the application in FPDs . Especially, metal halide perovskites (MHPs) exhibit outstanding performances including remarkable optical and electrical properties, low‐cost, low‐temperature solution‐processed fabrication, and compatibility with flexible substrates .…”