High-gain infrared-to-visible upconversion light-emitting phototransistors

Infrared-to-visible upconversion devices made by integrating an infrared quantum dot photodetector with an organic light-emitting diode potentially offer a route to low-cost, pixel-free infrared imaging. However, making such devices sufficiently efficient for practical use is a challenge. Here, we report a high-gain vertical phototransistor with a perforated metallic source electrode having an EQE up to 1 × 105% and a detectivity of 1.2 × 1013 Jones. By incorporating a phosphorescent organic light-emitting diode in this phototransistor, an infrared-to-visible upconversion LEPT with a photon-to-photon conversion efficiency of over 1,000% is demonstrated. An optoelectronic device that efficiently converts infrared light to visible light could prove useful for imaging applications.