Terahertz Detectors for 6G Technology Using Quantum Dot 3D Concave Convergence Microwheel Arrays

The 6G technology has defined 0.1–0.28 THz as the communication band. However, high-performance detectors in large areas at room temperature are still an enormous challenge. To greatly improve the performance of the THz detector, a room-temperature terahertz (THz) detector based on PbS quantum dot (QD) microwheel arrays have been designed and fabricated. The QD microwheel array was fabricated on a thin GaN/Si substrate and with the engraved periodic wheel. In addition, the concave convergence of the microwheel further improves the interaction between the terahertz wave and the device. The detector has been tested under the 6G communication frequencies of 0.14 and 0.28 THz and showed current responsivities of 3.12 and 4.67 A/W. The detector based on the QD microwheel array has shown a current responsivity up to 9 times higher compared with the signal QD film. The noise equivalent power valuesof the devices for 0.14 and 0.28 THz are 6.61 × 10–13 and 1.88 × 10–14 W/Hz1/2. The results give a chance to develop the large-area, high-performance THz detector based on QDs, which could provide a reliable alternative for 6G communication equipment at room temperature.