Abstract
Energy harvesting rectennas require ultrafast rectifying diodes that are efficiently matched to the optical nanoantenna. These diodes should possess low on-resistance and high responsivity. Here, we introduce a metal-insulator-metal diode composed of a new material, Ti-TiO2-Al. This diode has a 1.0 nm ultrathin insulator layer fabricated using atomic layer deposition (ALD). It has a zero-bias resistance of 275 Ω and a maximum responsivity of 3.1 A/W. To further improve its performance, another ultrathin layer of ZnO was added. The proposed Ti-TiO2/ZnO-Al metal-insulator-insulator-metal diode has a zero-bias resistance of 312 Ω and a maximum responsivity of 5.1 A/W. The two types of diodes are fabricated on a SiO2 substrate using conventional photolithography and ALD. Between 20 °C and 55 °C, the I-V characteristics did not show much temperature dependence. The effective barrier height, dielectric constant, and electron effective mass in each insulator are extracted using a constrained and derivative-based optimization algorithm.
Highlights
The continuing rise in energy demand worldwide has been a strong motivation to investigate untapped renewable energy sources
We report on a fabricated MIM diode and an improved version, the metal-insulator-insulator-metal (MIIM) diode, with the goal to achieve both low zero-bias resistance and high responsivity
The maximum responsivity is calculated as 3.1 A/W at 120 mV, where the corresponding resistance is 200 Ω
Summary
The continuing rise in energy demand worldwide has been a strong motivation to investigate untapped renewable energy sources. Rectennas are high-efficiency devices that transform infrared radiation into DC output currents Since it was first proposed for harvesting of solar irradiation, several groups have examined its feasibility and have developed technologies to achieve reproducible and efficient energy harvesting devices. We report on a fabricated MIM diode and an improved version, the metal-insulator-insulator-metal (MIIM) diode, with the goal to achieve both low zero-bias resistance and high responsivity. Insulator layers with a small difference in their electron affinities, in addition to low metalinsulator barrier heights, are preferable These requirements lead to selecting the MIM material combination for our proposed Ti-TiO2Al diode. To further improve the responsivity of this diode, an MIIM diode, with TiO2 and ZnO insulating layers, is proposed to achieve higher responsivity while keeping the resistance low. The proposed Ti-TiO2/ZnO-Al MIIM diode with a 1-nm thick TiO2 layer and a 0.5-nm thick ZnO layer allows electron conduction through the oxides by tunneling to dominate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
