High Dielectric Transparent Film Tailored by Acceptor and Donor Codoping

High dielectric constant materials are of particular current interests as indispensable components in transistors, capacitors, etc. In this context, there are emerging trends to exploit defect engineering in dielectric ceramics for enhancing the performance. However, demonstrations of similar high dielectric performance in integration-compatible crystalline films are rare. Herein, such a breakthrough via the functionalization of donor-acceptor dipoles by compositional tuning in Ga-Cu codoped ZnO films is reported. The dielectric constant reaches similar to 200 at 1 kHz and the optical transmittance in visible light reaches similar to 80%. Importantly, by analyzing the impedance spectroscopy data, prominent relaxation mechanisms in correlation with the dipole properties, enabling consistent explanations of the dielectric constant as a function of frequency are discriminated. The atomistic nature of the dipoles is revealed by the systematic X-ray spectroscopy analysis. Spectacularly, similar trends for the dielectric properties are observed, while synthesizing samples by pulsed laser deposition and ion implantation, indicating the general character of the phenomena.

Automated summary

This study reports a breakthrough in achieving high dielectric performance in crystalline films through the functionalization of donor-acceptor dipoles by compositional tuning in Ga-Cu codoped ZnO films. The dielectric constant reaches around 200 at 1 kHz and the optical transmittance in visible light reaches around 80%. By analyzing impedance spectroscopy data, prominent relaxation mechanisms related to the dipole properties were identified, providing consistent explanations of the frequency-dependent dielectric constant.