Doped Organic Semiconductors for Infrared Detection

Abstract

Organic semiconductors offer unique advantages for infrared (IR) detection, such as mechanical flexibility and spectral tunability. However, the wavelength range of organic photodiodes is limited to the short-wave IR region. Here, it is demonstrated that by employing a bolometer device architecture comprising solution or vacuum-deposited doped organic semiconductors, the detection range can be extended beyond 10 µm, reaching detectivities as high as 8·10⁹ Jones. While thermal detectors such as bolometers are typically slower than photonic detectors, it is shown that reducing the total device thickness enables response times down to 41 ms, which is sufficient for imaging applications. It is further illustrated that the low thermal conductivity of organic semiconductors allows pixel sizes of 10 µm, which are still compatible with a detectivity ≈109 Jones when the total device thickness is kept below 1000 nm. These findings highlight the strong potential of organic bolometers, particularly in applications where spectral reach is critical.