image: Figure | Peculiarities of room temperature organic photodetectors.a) The carriers’generation mechanisms in OSCs: photoexcitation, exciton dissociation, charge carrier transport, and recombination and extraction processes required to extract free charge. b) The room temperature D* for OSC based detectors compared with typical market detectors (AlGaN, Si, Ge, InGaAs PDs and PMTs) for λ =0.2–2 μm. The utmost SFL and BLIP are also presented. PD-photodiode, PMT-photomultiplier tube, FET-field effect transistor, PV-photovoltaic detector. The OSC photodetectors’ D* marked in magenta are overestimated.
Credit: Piotr Martyniuk et al.
In a new paper published in Light: Science & Applications, a team of scientists, led by Professor Antoni Rogalski from Institute of Applied Physics, Military University of Technology, Poland and Professor Weida Hu from State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, China have reported on the “Peculiarities of room temperature organic photodetectors”. This paper attempts to explain the organic photodetectors’ peculiarities when confronted with typical devices dominating the commercial market. To achieve this goal, the paper first briefly describes OSC deposition techniques, diametrically opposed to those used for standard semiconductors. This was followed by a more detailed discussion of basic physical properties, contributing to the photodetectors’ performance including absorption coefficient, conduction mechanism, charge generation and charge transport. These effects are very different from those found in inorganic semiconductors (ISCs).
In addition, Authors described the main modes of OSC based photodetectors [photoconductors, photodiodes and field effect transistor photodetectors (FET)] with emphasis on their special features that distinguish them from standard photodetectors. Final part of the paper shows current state-of-the-art of various types/structures of photodetectors and routes for further improvement. The upper detection limit for OSC photodiodes has been shown to be comparable to that for ISC photodiodes, but the spread of these values is about three orders of magnitude. The D* overestimates (especially organic based FET phototransistors) were explained.
Journal
Light Science & Applications
Article Title
Peculiarities of room temperature organic photodetectors