An electrical and infrared controllable color emission quantum dot light-emitting diode

Infrared-to-visible upconversion (IVU) possesses a variety of applications, spanning from bio-imaging to anti-counterfeiting, and has attracted great attention. However, the devices developed in previous studies suffer from several drawbacks, such as relatively weak optical absorption, requirement of a complicated design, and a costly fabrication process, which limit their potential practical application. To circumvent the existing difficulties, in this study, an IVU device based on infrared quantum dots (QDs) and a mixture of visible QD light-emitting diodes (QLEDs) with low operational voltage and multiple changeable visible colors is demonstrated. The emission color of this IVU-QLED can be easily manipulated under different input currents and power densities of incident infrared radiation. The IVU-QLED device can also be achieved with cost-effective and simple solution fabrication processes. In addition, this dual electrical-optical modulated IVU-QLED shows a fast response time. With the unexplored features of IVU, including infrared-visible upconversion, tunable visible color emission, dual functional modulation, and cost-effectiveness, the designed IVU-QLEDs shown here provide an alternative route for the development of untouched optoelectronic devices, which should be very useful and timely for future applications covering anti-counterfeiting, infrared sensing, bio-imaging, night vision, etc.