Microgrooves Array on Phase-Change Germanium-Antimony-Tellurium Alloys Nanofilm THz Detector
Qi Song, Wei Chen, Jiachen Yang, Min Zhang, Feilong Gao, Bingyuan Zhang, Bo Dong, Peiguang Yan, Yanqing Lu
Abstract
Instead of utilizing commercial detectors and a detection scheme based on 2-D layer semiconductors or surface plasmon enhancement effect, we have developed a novel terahertz (THz) detector consisting of an array of microgrooves. This device combines the exceptional performance of materials with the localized surface plasmon (LSP) effect in a sub-wavelength structure electromagnetic-induced well detector. At room temperature, our device achieves a detectivity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}^{\ast }$ </tex-math></inline-formula> ) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${6.3} \times {10}^{{8}}$ </tex-math></inline-formula> cm Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {1/2}}$ </tex-math></inline-formula> pW <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 a responsivity (Rv) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${3.31} \times {10}^{{5}}$ </tex-math></inline-formula> V <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{W}^{-{1}}$ </tex-math></inline-formula> at 0.1 THz, with a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$20 \mu \text{m}$ </tex-math></inline-formula> line spacing array. Furthermore, the effective detection area of our device is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.5\times2$ </tex-math></inline-formula> mm, making it much more suitable for practical applications. These high-performance THz wave photodetectors open up possibilities for the effective detection of THz waves, which have wide-ranging applications in areas such as high-capacity communications, THz radar, biological diagnosis, and THz detection.