Image sensors based on quantum dots

The company’s so-called QuantumFilm technology was developed by InVisage after years of research under the guidance of the company’s chief technical officer, Ted Sargent.

The technology is based on quantum dots – semiconductors with unique light-capture properties. QuantumFilm works by capturing an imprint of a light image on the quantum dots and then employs the silicon beneath it to read out the image and turn it into digital signals.

InVisage spent three years engineering the quantum-dot material to produce image sensors that could be integrated with standard CMOS manufacturing processes.

Just nanometres in size, the quantum-dot-based material is deposited directly on top of the wafer during manufacturing. The material is added as a final wafer-level process, which allows for easy integration into standard semiconductor foundries. The process – akin to coating a layer of photoresist onto a standard wafer – adds minimal cost on top of the standard layers of silicon processes.

Silicon-based image sensors – the technology used today for all digital cameras, including handheld, professional, mobile-phone, security and automotive cameras – capture, on average, 25 per cent of light. QuantumFilm, on the other hand, is claimed to capture 90-95 per cent, enabling better pictures even in the most challenging lighting conditions.