Broadband Infrared to Terahertz Detection Based on Pyramidal Polymer-Derived Ceramic Array Absorber

In this study, we prepared polymer-derived ceramics (PDCs) materials with 3-D pyramid array surface and reported the enhancement in infrared (IR) to terahertz (THz) absorption, which leads to improvement in broadband response for a Mn-Co-Ni-O bolometer. The pyramidal array-shaped PDC materials with varying gap to period ratios were prepared via a pyrolysis process of a crosslinked polydimethylsiloxane (PDMS) precursors transferred from silicon molds. The PDMS exhibits high broadband absorption efficiency across the IR to THz range. The PDC absorber demonstrates excellent absorptance in both the IR (1400–15000 cm<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula>) and THz (507–519 GHz) regions due to its enhanced capability in capturing IR and THz photons. In comparison to planar PDC surfaces with a reflectivity of 20%, pyramidal surfaces exhibit significantly lower values ranging from 4% to 7% when measured at an incidence and receiving angle of 60° in THz range. By integrating a pyrolyzed PDC absorber as an absorber with a Mn-Co-Ni-O (MCNO) bolometer, there is a substantial enhancement in photothermal conversion efficiency. The MCNO-PDC bolometer exhibits a remarkable increase in responsivity by 308% at 0.512 THz compared to the MCNO detector. Moreover, the detector achieves a detectivity of up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.6\times 10^{{7}}~\text {cm}\cdot \text {Hz}^{{0.5}}$ </tex-math></inline-formula>/W, covering a broadband ranging from 0.635 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$592~\mu $ </tex-math></inline-formula>m. The integration of PDC materials not only improves the absorption efficiency of the detector across a wide spectrum but also ensures high uniformity in broadband response. These findings demonstrate the potential of the MCNO-PDC detector for high-performance broadband optoelectronic applications.