Center for Physical Sciences and Technology, Saulėtekio Ave. 3, LT-10257 Vilnius, Lithuania.
Vilnius Gediminas Technical University, Saulėtekio Ave. 11, LT-10223 Vilnius, Lithuania.
Sensors (Basel). 2023 Jan 28;23(3):1441. doi: 10.3390/s23031441.
The application of the unique properties of terahertz radiation is increasingly needed in sensors, especially in those operating at room temperature without an external bias voltage. Bow-tie microwave diodes on the base of InGaAs semiconductor structures meet these requirements. These diodes operate on the basis of free-carrier heating in microwave electric fields, which allows for the use of such sensors in millimeter- and submillimeter-wavelength ranges. However, there still exists some uncertainty concerning the origin of the voltage detected across these diodes. This work provides a more detailed analysis of the detection mechanisms in InAlAs/InGaAs selectively doped bow-tie-shaped semiconductor structures. The influence of the InAs inserts in the InGaAs layer is investigated under various illumination and temperature conditions. A study of the voltage-power characteristics, the voltage sensitivity dependence on frequency in the K range, temperature dependence of the detected voltage and its relaxation characteristics lead to the conclusion that a photo-gradient electromotive force arises in bow-tie diodes under simultaneous light illumination and microwave radiation.
太赫兹辐射的独特性质在传感器中的应用需求日益增长，特别是在那些无需外部偏置电压即可在室温下工作的传感器中。基于 InGaAs 半导体结构的蝴蝶结型微波二极管满足这些要求。这些二极管基于微波电场中的自由载流子加热工作，这使得这些传感器能够在毫米波及亚毫米波段使用。然而，对于这些二极管中检测到的电压的起源，仍然存在一些不确定性。本工作对 InAlAs/InGaAs 选择性掺杂蝴蝶结型半导体结构中的检测机制进行了更详细的分析。在不同的照明和温度条件下，研究了 InGaAs 层中的 InAs 插入物的影响。对电压-功率特性、K 波段检测电压的频率灵敏度依赖性、检测电压的温度依赖性及其弛豫特性的研究得出结论，在同时进行光照明和微波辐射的情况下，蝴蝶结二极管中会产生光梯度电动势。
