Recent advances with optical upconverters made from all-organic and hybrid materials

Abstract

The growing interest in near-infrared (NIR) imaging is explained by the increasing number of applications in this spectral range, which includes process monitoring and medical imaging. NIR-to-visible optical upconverters made by integrating a NIR photosensitive unit with a visible emitting unit convert incident NIR light to visible light, allowing imaging of a NIR scene directly with the naked eye. Optical upconverters made entirely from organic and hybrid materialswhich include colloidal quantum dots, and metal-halide perovskitesenable low-cost and pixel-free NIR imaging. These devices have emerged as a promising addition to current NIR imagers based on inorganic semiconductor photodiode arrays interconnected with read-out integrated circuitry. Here, we review the recent progress in the field of optical upconverters made from organic and hybrid materials, explain their functionality and characterization, and identify open challenges and opportunities.

Organic Upconversion Imager with Dual Electronic and Optical Readouts for Shortwave Infrared Light Detection

“…An alternate approach that circumvents the need for ROIC pixilation is based on upconversion imaging devices, which consist of a SWIR photodetector working in conjunction with a visible light‐emitting diode. [ 8 ] Low energy SWIR photons absorbed in the detection layer are locally upconverted into high energy photons at the emissive layer, providing a visible image of the incident infrared pattern. The direct upconversion process allows the imager to be pixel‐less; that is, it does not rely on pixelated backplanes to register spatial variations of the incoming SWIR light.…”

“…We note that prior work [ 8 ] has used blocking layers to tune the radiative recombination zone in upconversion imagers. Here, we demonstrate another benefit of the NPB blocking layer, in which it minimizes the loss of photogenerated charges due to non‐radiative recombination in the BHJ.…”

Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices

“…The status and progress until 2018 for optical upconverters that are entirely made with organic and hybrid materials [ 14 ], including perovskites and quantum dots, is summarized in reference [ 15 ]. Since then, several solution-processed upconverters based on quantum dots were reported [ 11 , 16 , 17 ].…”

Facile Fabrication of SrTiO3@MoS2 Composite Nanofibers for Excellent Photodetector Application

“…As we all know, water pollution, greenhouse effect, and fumes are hazardous to human beings, but few people notice that potential light pollution is also threatening our health [1][2][3][4]. Light is everywhere in our life; in fact, proper sunlight is useful for our health.…”