The effect of electrode shape on Schottky barrier and electric field distribution of flexible ZnO photodiode

Abstract

In this study, the effect of electrode shape difference on the height of the Schottky barrier and the electric field in flexible photodiodes (PDs) has been investigated. For this purpose, three different electrode designs were prepared on three flexible FR4 layers that were coated with Zinc Oxide (ZnO). The printing circuit board (PCB) method was used to create these copper electrodes. The asymmetry of the PD electrodes and the difference in the height of the Schottky barrier has led to the creation of self-powered PDs. The effect of the amount and shape of the distribution of internal electric fields generated in the PDs and its effect on the parameters of the PDs has been investigated with the help of simulations performed in COMSOL software. The photocurrent of the sample with circular and rectangular electrodes was equal to 470 µA in 15 V bias, which was twice as good as a sample with an interdigitated MSM structure. Also, this sample had the best response time among these three samples, which was equal to 440 ms.

Fast Lithium Niobate Photodetector

“…The shape of the electrodes affects the electric field distribution, carrier transport, and leakage pathways within the device, thereby impacting the dark current. [43,44] In our experiments, seven LN detectors share common electrode pads. Only one photodetector is photoexcited and contributes to the photocurrent, while all seven sets of photodetectors, as well as the common electrode pads, contribute to the dark current, as sketched in the inset of Figure 1c.…”

“…Only one photodetector is photoexcited and contributes to the photocurrent, while all seven sets of photodetectors, as well as the common electrode pads, contribute to the dark current, as sketched in the inset of Figure 1c. To mitigate the dark current and improve responsivity, alternative electrode designs, such as concentric circular electrodes [ 44 ] and matching the incident light illumination shape to the electrode shape of the device [ 45 ] can be employed. Furthermore, it is noteworthy that LN:Mg exhibits a smaller dark current, indicating a higher resistance.…”