Surface plasmon induced direct detection of long wavelength photons

Jinchao Tong,Zhiming Huang,Yue Qu,Dao Hua Zhang,Wei Zhou,Zhengji Xu

doi:10.1038/s41467-017-01828-2

Abstract

Millimeter and terahertz wave photodetectors have long been of great interest due to a wide range of applications, but they still face challenges in detection performance. Here, we propose a new strategy for the direct detection of millimeter and terahertz wave photons based on localized surface-plasmon-polariton (SPP)-induced non-equilibrium electrons in antenna-assisted subwavelength ohmic metal–semiconductor–metal (OMSM) structures. The subwavelength OMSM structure is used to convert the absorbed photons into localized SPPs, which then induce non-equilibrium electrons in the structure, while the antenna increases the number of photons coupled into the OMSM structure. When the structure is biased and illuminated, the unidirectional flow of the SPP-induced non-equilibrium electrons forms a photocurrent. The energy of the detected photons is determined by the structure rather than the band gap of the semiconductor. The detection scheme is confirmed by simulation and experimental results from the devices, made of gold and InSb, and a room temperature noise equivalent power (NEP) of 1.5 × 10−13 W Hz−1/2 is achieved.

Highlights

Millimeter and terahertz wave photodetectors have long been of great interest due to a wide range of applications, but they still face challenges in detection performance
We propose a strategy for direct detection of long-wavelength photons (LWPs) in the millimeter and terahertz wave ranges, based on localized SPP-induced non-equilibrium electrons in an antennaassisted subwavelength ohmic metal–semiconductor–metal (OMSM) structure
In this paper, we proposed antenna-assisted subwavelength OMSM structures for direct detection of LWPs in the millimeter and terahertz wave ranges via localized SPP-induced non-equilibrium electrons in a low-plasma-frequency and high-electronmobility semiconductor strip of subwavelength dimension

Summary

Introduction

Millimeter and terahertz wave photodetectors have long been of great interest due to a wide range of applications, but they still face challenges in detection performance. We propose a new strategy for the direct detection of millimeter and terahertz wave photons based on localized surface-plasmon-polariton (SPP)-induced non-equilibrium electrons in antenna-assisted subwavelength ohmic metal–semiconductor–metal (OMSM) structures. Based on thermal sensing mechanisms, the first three either suffer from a slow response (only up to a few hundred hertz modulation frequency for Golay cells and pyroelectric elements, though their noise equivalent power (NEP) can be as low as 10−10 W Hz−1/2 at room temperature9) or require cryogenic cooling for normal operation (4.2 K for typical Si bolometers). A novel tunable hot-carrier LWP detector based on hot–cold carrier energy transfer at low temperatures (T < 30 K) was reported[21], which enabled a very long-wavelength infrared response up to 55 μm (5.5 THz)

Methods

Results

Conclusion