Bias Dependence of Organic-Oxide Phototransistors with Peak Infrared Absorption at 1550 nm

Abstract

Photodetectors operating across the short-wave infrared region are essential elements of modern optoelectronic technologies. This work demonstrates the integration of an organic bulk heterojunction polymer layer on an oxide thin-film transistor to achieve a peak infrared photoresponse at 1550 nm. As the efficiency of organic semiconductors decreases at longer wavelengths, the phototransistor structure uses trap-assisted charge injection to enhance the photoresponse. This work optimizes the detector performance by investigating the balance between bias stress and signal-to-noise under different bias conditions, enabling a responsivity at 1550 nm up to 130 mA/W at a low light intensity of 2.5 × 10–5 W/cm2.

Improvement in Performance and Stability of PbS QD/IGZO Phototransistors Through the Introduction of Ga2O3 Film for Broadband Sensor Applications

“…Visible light pulses could be attributed to the photoinduced transition of V O into V O 2+ , leading to the net creation of free carriers in the conduction band. However, the conversion of V O required high activation energy (>1.0 eV), which occurred under visible light. , Thus, the increased peak I D behavior under NIR exposure would be attributed to the coupling between PbS QDs and the IGZO channel layer with a narrow E G , mitigating the trapping of photocreated EHPs . It is worth noting that the off-state leakage current characteristics of the phototransistor efficiently recovered within approximately 30 s (refer to Figure S13).…”