P-Type α-CuGaO₂ Electronics: A Study on Gap States and Fermi Level Pinning and a Solution to Schottky to Ohmic Transition for Electronic Applications

Abstract

Delafossite CuGaO2 (CGO) as an emerging semiconductor is considered as a promising p-type material in electro-optics. The use of CGO in the semiconductor industry requires addressing the challenges encountering this material. One of the most significant issues in the technology development for the inclusive usage of this material is the proper choice of electrical connection. The Schottky barrier formed at the CGO/metal interface can be a restrictive and/or effective factor in electron transfer in electronic and electro-optical devices. In addition, the imperative Fermi level pinning (FLP) phenomenon makes the proper choice of the metal contact more thoughtful. In this research, we study the electronic properties of the CGO/metal interface and take into account the FLP phenomenon to select the appropriate metal contact for the required operation of the CGO-based devices. We look more closely at the Schottky to Ohmic connection transition. Technology computer-aided design (TCAD) simulations show that the FLP effect alters the Schottky barrier height (SBH) between CGO and the metal contact, reducing the dependence of the SBH on the metal’s work function. The hole concentration in CGO is varied between 1014 and 1021 cm–3, which changes the SBH and the Schottky to Ohmic transition condition. The results show that the CGO-based photodetector may get a responsivity of 0.371 and 5.570 A/W, respectively, for the Schottky and Ohmic modes.

Investigating various metal contacts for p-type delafossite α-CuGaO2 to fabricate ultraviolet photodetector

“…As we mentioned in our previous research 29 on simulated CGO-based PDs, the behavior of the system for metal work functions lower than 5.1 eV cannot be Ohmic. However, in the current research, the Ag electrode with the work function of 4.7 eV exhibits linear behavior.…”

“…In previous research 29 , we explored the electronic properties of α-CGO by investigating the Fermi level pinning (FLP) effect in this material and simulated an α-CGO-based UV-PD. Herein, we experimentally synthesize α-CGO films by a facile and scalable method and then investigate its structural, optical, and electronic properties.…”

Enhanced photoresponse of the CdS microwire photodetectors based on indium ion implantation

“…The I-V curves at different laser power intensities are presented in figure 4(a). The nonlinear behavior suggests the formation of apparent Schottky contacts between the CdS microwire and In metal electrodes, resulting from the change in working function of the CdS nanowires due to the In ion implantation [37][38][39]. The Kelvin probe force microscope results are shown in figure S3.…”

A novel algorithm for maximum power point tracking using computer vision (CVMPPT)

“…Adding by-pass diodes increases the non-linearity of a photovoltaic system and generates multiple peaks in its P-V curve [14][15][16]. To extract the maximum power of a photovoltaic system it is necessary for it to work in the global maxima [17].…”