Abstract
Omnipresent quality monitoring in food products, blood-oxygen measurement in lightweight conformal wrist bands, or data-driven automated industrial production: Innovation in many fields is being empowered by sensor technology. Specifically, organic photodetectors (OPDs) promise great advances due to their beneficial properties and low-cost production. Recent research has led to rapid improvement in all performance parameters of OPDs, which are now on-par or better than their inorganic counterparts, such as silicon or indium gallium arsenide photodetectors, in several aspects. In particular, it is possible to directly design OPDs for specific wavelengths. This makes expensive and bulky optical filters obsolete and allows for miniature detector devices. In this review, recent progress of such narrowband OPDs is systematically summarized covering all aspects from narrow-photo-absorbing materials to device architecture engineering. The recent challenges for narrowband OPDs, like achieving high responsivity, low dark current, high response speed, and good dynamic range are carefully addressed. Finally, application demonstrations covering broadband and narrowband OPDs are discussed. Importantly, several exciting research perspectives, which will stimulate further research on organic-semiconductor-based photodetectors, are pointed out at the very end of this review.
Highlights
Photodetectors (PDs), often called photosensors, convert incoming optical signals into electrical signals and are widely employed for imaging,[1] medical diagnostics,[2,3] distance measuring,[4] optical signal communication, etc.[5]
In 2020, Xing et al introduced self-filtering narrowband organic photodetectors (OPDs) composed of a depletion layer, a donor and a thin acceptor layer, forming a planar heterojunction (PHJ).[83]
We summarized the status, recent progress and current challenges of narrowband OPDs
Summary
Photodetectors (PDs), often called photosensors, convert incoming optical signals into electrical signals and are widely employed for imaging,[1] medical diagnostics,[2,3] distance measuring,[4] optical signal communication, etc.[5]. Compared to their inorganic counterparts, avalanche photomultiplication, where one photogenerated charge carrier can induce several free carriers under high applied external electric field, cannot be achieved in OPDs: this is caused by the disordered nature and high exciton binding energy of organic materials.[44,45,46] Instead, a different principle was introduced by Hiramoto et al in 1994.47 Since PM-OPDs with photocurrent gain, achieved by trap-state-induced tunneling injection of charge carriers, were broadly investigated.[25,48,49,50] Similar to the previously described organic phototransistors, PM type OPDs can pave the way for improving the performance of traditional PDs under low light intensity or in low absorption wavelength regions (e.g. NIR). The detection mode of OPDs is generally divided into photovoltaic (PV) or self-powered mode at zero bias and extraction mode at reverse bias
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
