Large-scale fabrication of CMOS-compatible silicon-OLED heterojunctions enabled infrared upconverters

Abstract

Infrared-to-visible upconverters have widespread application prospects, including bioimaging, night vision, and defense security. A typical upconverter is generally constructed by integrating an infrared photodetector (PD) detecting low-energy infrared with a visible light-emitting diode (LED) emitting high-energy visible light. However, when photocarriers transport through the interface between PD and LED, lateral current spreading is inevitably present, which leads to optical cross-talking and hinders the realization of high-resolution and large-area infrared imaging. Here, near-infrared (NIR) upconverters are fabricated via the integration of silicon (Si) NIR detectors with organic LED (OLED) by complementary metal–oxide–semiconductor compatible manufacturing processes. The pixelated indium tin oxide electrodes introduced as the interfacial carrier transfer channel effectively suppress the lateral current spreading and ensure that the photogenerated carrier of PD could transport into the OLED with a well-defined spatial resolution. The Si-OLED upconverters possess a wafer-level luminous area and large-scale fabrication capacity and realize high-resolution infrared imaging with a resolution as high as 3629 dpi. By changing the organic luminescent layer of OLED, the Si-OLED upconverters could emit red/green/blue visible light under NIR illumination with a low turn-on voltage of 3 V and an excellent upconversion efficiency of 9.2%. Furthermore, the large-area Si-OLED upconverters exhibit flexibility with an infrared upconversion ability even under bending.