Elaborating the interplay between the detecting unit and emitting unit in infrared quantum dot up-conversion photodetectors

Abstract

The quantum dot up-conversion device combines an infrared photodetector (PD) and a visible quantum-dot light-emitting diode (QLED) to directly convert infrared target to visible image. However, large efficiency loss is...

Infrared-Light Visualization by Organic Upconversion Devices

“…Meanwhile, the optical properties of each layer should be carefully designed and optimized to maximize the photoresponse and avoid visible-light trapping and blocking. 18,19…”

“…As a result, the energy level engineering between the multiple layers in the upconversion device decides the overall upconversion efficiency and dark current. Meanwhile, the optical properties of each layer should be carefully designed and optimized to maximize the photoresponse and avoid visible-light trapping and blocking. , …”

“…These results are encouraging for the design of organic upconversion imagers for different wavebands. To facilitate human eye vision, green organic LEDs are most frequently employed in upconversion devices since human eyes are naturally sensitive to green photons. , Some other light-emitting materials, e.g., perovskites and quantum dots, exhibiting high purity in their electroluminescence spectrum ,, can also be utilized for upconversion imagers.…”

Unraveling the efficiency losses and improving methods in quantum dot-based infrared up-conversion photodetectors

“…However, when the CQDs-based PD and QLED were integrated into the up-conversion photodetectors, the highest reported η pp was only 6.5%, which was much smaller than the IPCE × EQE product (i.e., 10 4 % × 25% = 2500%). In previous works, the efficiency of the all-CQD up-conversion devices was improved by adjusting the optimized working voltages of the QLED unit 29 or the optimized thickness of the infrared absorbing layer in the PD unit (our previous work) 30 . However, these improvements were just based on empirical experiences and experimental attempts, and there haven't been sufficient understandings on the origins of the huge efficiency losses after the high-performance PDs and QLEDs are integrated together to form up-conversion photodetectors.…”

Sn-doped ZnO for efficient and stable quantum dot light-emitting diodes via a microchannel synthesis strategy

“…Colloidal quantum dots (QDs) have great potential applications in numerous optoelectronic fields owing to their excellent optical properties, such as a tunable emission wavelength, narrow emission peaks, high photoluminescence quantum yields (PLQYs), etc . 1–8 In particular, QD-based light-emitting diodes (QLEDs) are the strongest candidates for future cost-effective displays due to their wide color gamut, flexibility and easy processability. Since the first QLED was reported, remarkable progress has been made and the external quantum efficiency (EQE) has been over the theoretical limit (20%), thus showing promise for use in real display applications.…”