Metasurface Colloidal Quantum Dot Photodetectors
Nikola Đorđević, Raphael Schwanninger, Maksym Yarema, Stefan M. Koepfli, Olesya Yarema, Yannick Salamin, Nolan Lassaline, Bojun Cheng, Nuri Yazdani, Alexander Dorodnyy, Yuriy Fedoryshyn, Vanessa Wood, Juerg Leuthold
Abstract
Efficient photodetectors that can be easily engineered for a specific spectral window are of high interest. Here, we report on the design, fabrication, and characterization of metasurface-enhanced photodetectors and photodiodes using colloidal quantum dots. We fabricate photoconductors optimized for the wavelength range around 1550 nm featuring responsivities of up to 8000 A/W with low noise equivalent powers on the order of tens of . Further, we produce photodiodes with responsivities of ∼5 mA/W that offer faster responses (14 μs rise time). The high responsivities are due to the metasurface, which increases the absorption by a factor of 10 compared to that of a quantum dot thin film of the same thickness and a structure that enables a photo-gain. We introduce a metasurface to detect either of the two orthogonal polarizations. The fabricated photoconductors operate at low voltages (1–5 V), making them compatible with the complementary metal-oxide-semiconductor (CMOS) read-out circuitry.