Facile preparation of broadband absorbers based on patternable candle soot for applications of optical sensors

Abstract

Efficient optical absorbers are critical for photo-related applications, and have attracted significant interest in material science and physics for decades. In this work, a broadband absorber based on candle soot is presented with an average absorption of 98.6% in a waveband of 400 nm–1.5 μm, and of 75.1% in a wavelength range as broad as 1.5–25 μm. Such an absorber can be prepared simply by using flame deposition, which is patternable and can adopt flexible substrates. By introducing the absorber onto optical sensors, an improvement of device output by 133% is achievable. It is expected that the absorber could provide a new approach for use of photo-absorption materials in a wide range of optical systems.