The extreme contagion of COVID-19 has driven us to rely on technology more than ever in an effort to preserve public health. The pandemic is putting pressure on some industries to find and adapt faster, more cost-effective ways for contactless operations, while also showing us where our capabilities are lacking. Innovation is progressing at lightning speed to keep up with the rapid changes everywhere, including healthcare, business, and even agriculture and manufacturing. Photodetectors – light-sensing devices – support much of this innovation, and they are behind much of the technology adapting to this new world.
- Temperature checks have become a routine precursor for reporting to work, going to an event, even before walking into a hospital. Temperature-sensing cameras are making their way into airports, malls and crowded cities to help control the potential of spreading disease.
- Consumers are now using the internet, tap-to-pay and QR codes to perform financial transactions.
- Facial recognition is becoming the preferred identification technique for those working in high-security jobs and accessing sensitive digital files – because scanning sensors don’t require touching surfaces that may be contaminated.
- In meat-packing and manufacturing facilities, special cameras can be used to see flaws and defects that are undetectable to the human eye, making it possible for employees to distance themselves while avoiding the meat shortages experienced early in the pandemic due to closures.
- In China and other regions of the world, autonomous driving is growing in use to transport medical supplies and food to healthcare workers and people living in regions with high rates of infection.
Tools using photodetectors have shifted from being the latest cool gadget to becoming an integral part of daily life. As we rely more and more on these technologies to support our transactions and interactions, improvement in the photodetectors used will drive innovation for higher-quality, more accurate, faster response time and reduced energy use. Nanotechnology innovations such as Quantum dots are the latest development that will take photodetection to the next level.
Incumbent Technology Can’t Keep Up
Before we get into quantum dots, it will be useful to understand near infrared detection and its importance in photodetection technology. Near infrared (NIR) light is not visible to the human eye, but it is key to enabling machines to make sense of the things they see. Analysis of NIR waves detected can indicate temperature, physical objects (to track their special features that are invisible for human eyes or see them in dark) and chemical composition, and it can even help detect unhealthy tissues in the body. Most photodetection technology relies on NIR light waves to analyze the environment or objects in question.
To sense NIR waves, photodetectors must contain materials that respond to the NIR spectrum of light. For example, when light irradiates a material, some of the electrons in the material are activated. These activated electrons trigger a response in the machine, which then provides information to the user such as temperature fluctuations, images and other background information.
Accessibility and functionality are the two main obstacles NIR photodetectors will need to overcome moving forward. The current state-of-the art products are made using InGaAs or Ge-based detectors, which are cumbersome and expensive to manufacture. The electrons in the NIR-sensitive material must have enough energy to move from the photodetector to the circuitry attached. Those circuits must be connected to the photodetector – which requires a process of tremendous precision in order to connect each pixel to the corresponding electronics. These photodetectors also require the use of larger quantity of materials which consume more energy than the emerging quantum dot technology. A combination of these problems makes it impossible to roll out the devices required to handle COVID-19 on the massive, global scale.
Quantum Dots Support Growing Technology
Quantum dots that are active in NIR range, such as QDot™ PbS, provide a solution to problems associated with the current product technology. They are less expensive to manufacture and integrate, and they allow for more precise detection as the pixel size can be decreased. Only a few tens of milligrams of these quantum dots are required per sensor, making the QDs themselves a very affordable option. Furthermore, quantum dots are compatible with silicon-based sensor electronics (which are affordable, but not sensitive enough toward the detection of NIR waves) and can be spin-coated, sprayed, printed or even brushed directly onto the surface of the detector. Quantum dots have a higher degree of sensitivity than InGaAs-based detectors and can be tuned to pick up a wider range of wavelengths in the NIR range.
Reproducibility is one of the most challenging elements of using quantum dots, because a difference of just a few nanometers in size can completely change the absorption range of the PbS QDs. Quantum Solutions, the leading manufacturer of NIR quantum dots, however, has perfected their manufacturing process. They can even tune their Qdots to best meet the requirements for individual applications. The company is set up to handle a large scale of quantum dot production, and they are prepared to handle the incoming demand for the burgeoning technology as we adapt to a post-COVID world.
Quantum Solutions Supports the Future of Photodetectors
The need for technology to support daily life is greater than it has ever been. We rely on advancements to help us stay safe and keep our world turning while we work to eliminate the global threat of a deadly virus. The more our lives depend on the technology in use, the more it should be affordable, accessible and responsive to our changing needs.
Photodetectors are the most important current technology for enabling a contactless, distanced reality. NIR quantum dots will be the driving force behind improvement and innovation in this field. Quantum Solutions enables this innovation by supplying these dynamic materials to the companies paving the way forward.