Search

Highly responsive organic photodetectors allow a plethora of applications in fields like imaging, health, security monitoring, etc. Photomultiplication‐type organic photodetectors (PM‐OPDs) are a desirable option due to their internal amplification mechanism. However, for such devices, significant gain and low dark currents are often mutually excluded since large operation voltages often induce high shot noise. Here, a fully vacuum‐processed PM‐OPD is demonstrated using trap‐assisted electron injection in BDP‐OMe:C60 material system. By applying only −1 V, compared with the self‐powered working condition, the responsivity is increased by one order of magnitude, resulting in an outstanding specific detectivity of ≈1013 Jones. Remarkably, the superior detectivity in the near‐infrared region is stable and almost voltage‐independent up to −10 V. Compared with two photovoltaic‐type photodetectors, these PM‐OPDs exhibit the great potential to be easily integrated with state‐of‐the‐art readout electronics in terms of their high responsivity, fast response speed, and bias‐independent specific detectivity. The employed vacuum fabrication process and the easy‐to‐adapt PM‐OPD concept enable seamless upscaling of production, paving the way to a commercially relevant photodetector technology. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Non-invasive monitoring of chick embryonic growth is addressed in this research. • Gender differences of incubated hatching eggs in terms of opacity during incubation is explained. • Classification models on gender of chick embryos before hatching are developed. Abstract In boiler production there is a gender biased preference for males, while for layer strains it is females. Thus, there is need for non-intrusive, early sex discrimination of chick embryos that is currently not being met. Hence, the motivation for the current study to investigate sex based growth difference in terms of opacity in order to classify the sex of incubated eggs. As a model, eggs from a broiler strain (ROSS 308) were sorted based on size, mass and shell color, and then incubated. During incubation an Embryonic Vital Scope, which consists of LEDs and a Si-photodiode integrated with amplifire that receives the light that passes through the egg, was used to measure average output voltage for individual eggs. After hatching feather sexing was used to determine the actual gender of the day-old chicks. A two-sample t -test was used to see the significant differences between male and female groups and gender classification model were developed using various algorithms. As the embryo became larger during incubation, the amount of transmitted light was reduced. Consequently, the opacity, the ratio of input LED current over average output voltage, increased. Male chick embryos showed higher opacity than female embryos (p-value <0.05). This method allowed us to determine the embryo gender before hatching with an accuracy of 84%. Although this method is still not 100% accurate, it is an important step towards developing an early, accurate and non-invasive means for sexing chick embryos in an industrial setting in the near future. [ABSTRACT FROM AUTHOR]

Here we report semi-transparent organic phototransistors (OPTRs), which consist of poly[{3-(5-(7-methyl-5,6-bis(octyloxy)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-6-(5-methylthiophen-2-yl)}-co-{2,5-bis(2-octyldodecyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione}] (PDPP-8OBT) as a sensing channel layer, for the detection of particular near infrared (NIR) light (905 nm) that is used in the light and distance ranging (LiDAR) systems. Two different thicknesses (45 and 75 nm) were chosen for the examination of NIR light-sensing performances, while both ca. 20 nm-thick silver source/drain electrodes and transparent indium-tin oxide (ITO) gate electrodes were applied to achieve the semi-transparency of devices. Results showed that the present devices could be operated in a mode of typical p-channel transistor and were sensitive to the NIR light. The semi-transparent OPTRs with the 75 nm-thick PDPP-8OBT layers showed better NIR light-sensing performances with the high photosensitivity of ca. 200 %. The performance of devices was slightly varied by running about 50 cycles of transfer curves between forward and backward sweeps, whereas the NIR light-sensing characteristics were well kept during the cycle tests. It is expected that the present NIR-OPTRs with the PDPP-8OBT sensing channel layers can be applied as a practical detector for LiDAR systems through further optimization of device stability. Semi-transparent organic phototransistors with the PDPP-8OBT sensing channel layers can detect near infrared (NIR) light with a high photosensitivity of ca. 200%. [Display omitted] • Synthesis of NIR light-absorbing conjugated polymer (PDPP-8OBT). • Semi-transparent organic phototransistors with the PDPP-8OBT sensing channel layers. • High photosensitivity (<200%) from the NIR-OPTRs with the PDPP-8OBT layers. [ABSTRACT FROM AUTHOR]