High-speed and high-precision PbSe/PbI2 solution process mid-infrared camera

Abstract

Infrared (IR) cameras based on semiconductors grown by epitaxial methods face two main challenges, which are cost and operating at room temperature. The alternative new technologies which can tackle these two difficulties develop new and facile material and methods. Moreover, the implementation of high speed camera, which makes high resolution images with normal methods, is very expensive. In this paper, a new nanostructure based on a cost-effective solution processed technology for the implementation of the high-speed mid-infrared light camera at room temperature is proposed. To this end, the chemically synthesized PbSe–PbI2 core–shell Quantum Dots (QDs) are used. In this work, a camera including 10 × 10 pixels is fabricated and synthesized QDs spin-coated on interdigitated contact (IDC) and then the fabricated system passivated by epoxy resin. Finally, using an electronic reading circuit, all pixels are converted to an image on the monitor. To model the fabricated camera, we solved Schrodinger–Poisson equations self consistently. Then output current from each pixel is modeled based on semiconductor physics and dark and photocurrent, as well as Responsivity and Detectivity, are calculated. Then the fabricated device is examined, and dark and photocurrents are measured and compared to the theoretical results. The obtained results indicate that the obtained theoretical and measured experimental results are in good agreement together. The fabricated detector is high speed with a rise time of 100 ns. With this speed, we can get 10 million frames per second; this means we can get very high-resolution images. The speed of operation is examined experimentally using a chopper that modulates input light with 50, 100, 250, and 500 Hz. It is shown that the fabricated device operates well in these situations, and it is not limited by the speed of detector. Finally, for the demonstration of the proposed device operation, some pictures and movies taken by the camera are attached and inserted in the paper.

Advances in solution-processed near-infrared light-emitting diodes

“…5a, Supplementary Table 1). Metal halide perovskites and QDs generally enable response speeds of ~100 ns 105,106 , whereas OSCs based on CT states have reached response times of 14.7 ns 107 . However, hybrid perovskite-polymer materials have reached high speeds of 5 ns 108 , whereas QDs recently attained an ultra-fast response of 74 ps (FWHM) 109 , by allowing carriers to be swept to the electrodes before they fall into the band tail states; these values indicate that these solution-based semiconductors will be soon appropriate for NIR-applications with high speed requirements.…”

Highly Responsive Mid-Infrared Metamaterial Enhanced Heterostructure Photodetector Formed out of Sintered PbSe/PbS Colloidal Quantum Dots

“…The synthesis of these colloids is well-studied and yields high-quality monodisperse CQDs. Lead chalcogenide CQDs have been successfully employed in the visible and NIR spectral ranges, but devices operating in the MIR have been scarcely reported and often perform worse than their bulk counterparts. − In order to combine the deposition advantages of CQDs and the performance of bulk materials, we have developed a liquid-phase spin-coating fabrication recipe, followed by a solid-state surface modification of CQDs (i.e., ligand exchange) and thin-film annealing step. The latter triggers microscale sintering of CQDs layers, enabling bulk-like transport and extended absorption to the MIR.…”

1D NiO–3D Fe2O3 mixed dimensional heterostructure for fast response flexible broadband photodetector

“…Certain photodetector applications require devices that have very narrow and selective spectral response to particular wavelengths. For example, night vision and temperature monitoring applications require peak spectral response in the infrared range with negligible response from other spectra [3]. Similarly, conventional imaging applications demand photodetectors that work only in visible region of the spectrum [4].…”