Organic photodetectors have promising applications in low-cost imaging, health monitoring and near-infrared sensing. Recent research on organic photodetectors based on donor–acceptor systems has resulted in narrow-band, flexible and biocompatible devices, of which the best reach external photovoltaic quantum efficiencies approaching 100%. However, the high noise spectral density of these devices limits their specific detectivity to around 1013 Jones in the visible and several orders of magnitude lower in the near-infrared, severely reducing performance. Here, we show that the shot noise, proportional to the dark current, dominates the noise spectral density, demanding a comprehensive understanding of the dark current. We demonstrate that, in addition to the intrinsic saturation current generated via charge-transfer states, dark current contains a major contribution from trap-assisted generated charges and decreases systematically with decreasing concentration of traps. By modeling the dark current of several donor–acceptor systems, we reveal the interplay between traps and charge-transfer states as source of dark current and show that traps dominate the generation processes, thus being the main limiting factor of organic photodetectors detectivity.

Organic/polymer transistors can enable the fabrication of large-area flexible circuits. However, these devices are inherently temperature sensitive due to the strong temperature dependence of charge carrier mobility, suffer from low thermal conductivity of plastic substrates, and are slow due to the low mobility and long channel length (L). Here we report a new, advanced characterization circuit that within around ten microseconds simultaneously applies an accurate large-signal pulse bias and a small-signal sinusoidal excitation to the transistor and measures many high-frequency parameters. This significantly reduces the self-heating and therefore provides data at a known junction temperature more accurate for fitting model parameters to the results, enables small-signal characterization over >10 times wider bias I–V range, with ~105 times less bias-stress effects. Fully thermally-evaporated vertical permeable-base transistors with physical L = 200 nm fabricated using C60 fullerene semiconductor are characterized. Intrinsic gain up to 35 dB, and record transit frequency (unity current-gain cutoff frequency, fT) of 40 MHz at 8.6 V are achieved. Interestingly, no saturation in fT − I and transconductance (gm − I) is observed at high currents. This paves the way for the integration of high-frequency functionalities into organic circuits, such as long-distance wireless communication and switching power converters.

In spite of interesting features as flexibility, organic thin-film transistors have commercially lagged behind due to the low mobilities of organic semiconductors associated with hopping transport. Furthermore, organic transistors usually have much larger channel lengths than their inorganic counterparts since high-resolution structuring is not available in low-cost production schemes. Here, we present an organic permeable-base transistor (OPBT) which, despite extremely simple processing without any high-resolution structuring, achieve a performance beyond what has so far been possible using organic semiconductors. With current densities above 1 kA cm−2 and switching speeds towards 100 MHz, they open the field of organic power electronics. Finding the physical limits and an effective mobility of only 0.06 cm2 V−1 s−1, this OPBT device architecture has much more potential if new materials optimized for its geometry will be developed.

An optimized vertical organic permeable-base transistor (OPBT) competing with the best organic field-effect transistors in performance, while employing low-cost fabrication techniques, is presented. The OPBT stands out by its excellent power efficiency at the highest frequencies.

Today's organic electronic devices, such as the highly successful OLED displays, are based on disordered films, with carrier mobilities orders of magnitude below those of inorganic semiconductors like silicon or GaAs. For organic devices such as diodes and transistors, higher charge carrier mobilities are paramount to achieve high performance. Organic single crystals have been shown to offer these required high mobilities. However, manufacturing and processing of these crystals are complex, rendering their use outside of laboratory‐scale applications negligible. Furthermore, doping cannot be easily integrated into these systems, which is particularly problematic for devices mandating high mobility materials. Here, it is demonstrated for the model system rubrene that highly ordered, doped thin films can be prepared, allowing high‐performance organic devices on almost any substrate. Specifically, triclinic rubrene crystals are created by abrupt heating of amorphous layers and can be electrically doped during the epitaxial growth process to achieve hole or electron conduction. Analysis of the space charge limited current in these films reveals record vertical mobilities of 10.3(49) cm2 V−1 s−1. To demonstrate the performance of this materials system, monolithic pin‐diodes aimed for rectification are built. The f3db of these diodes is over 1 GHz and thus higher than any other organic semiconductor‐based device shown so far. It is believed that this work will pave the way for future high‐performance organic devices based on highly crystalline thin films.