Transparent near-infrared organic upconversion device for high-quality biological imaging

Organic upconversion devices (OUDs), which have the advantages of low cost, simple structure, and large-area manufacturing, have emerged as a dependable infrared imaging strategy in the context of the growing interest in infrared visualization technology in recent years. However, currently available organic upconversion devices rarely make use of transparent electrode designs and imaging applications. In this work, since the transparent organic light-emitting diode (OLED) can emit visible light directly from the top electrode, we propose a transparent OUD integrating an organic photodetector and a transparent OLED to increase the transmission of visible light. The device achieves a notable upconversion efficiency of 10.9 % along with a wide linear dynamic range (LDR) of 77 dB and a low turn-on voltage (V_on) of 1.55 V. The device tackles the problem of inferior imaging quality that is linked to traditional oblique incidence techniques, thereby achieving high-quality imaging of biological specimens and visualization of intricate details that are imperceptible to the naked eye. This work provides modified imaging techniques and a fabrication method for next generation transmissive up-conversion devices.