【Epitaxy Papers】Unveiling the effect of swift gold ion irradiation on the performance of MOCVD-grown zinc gallium oxide thin film-based photodetector

      Researchers from Indian Institute of Technology Delhi have published a dissertation titled " Unveiling the effect of swift gold ion irradiation on the performance of MOCVD-grown zinc gallium oxide thin film-based photodetector " in Materials Science in Semiconductor Processing.

Abstract

      Understanding the role of irradiation-induced defects in wide-bandgap semiconductors is crucial for developing irradiation-tolerant optoelectronic devices. In this work, the influence of 120 MeV gold ion irradiation on the structural, optical, and photodetection properties of ZnGa₂O₄ thin films was systematically investigated. Controlled defect landscapes were introduced using ion fluences of 10¹² to 10¹³ ions/cm², followed by comprehensive multi-technique characterization to probe irradiation-driven modifications. The results reveal pronounced structural distortion and surface morphological evolution, accompanied by an apparent narrowing of the optical bandgap following irradiation. The photocurrent exhibited a strong fluence-dependent suppression, decreasing from 4.73×10⁻⁸ A for the pristine film to 4.11×10⁻¹⁰, 3.29×10⁻¹⁰, and 2.72×10⁻⁴ A for fluences of 10¹², 7×10¹², and 10¹³ ions/cm², respectively. This degradation was primarily ascribed to irradiation-induced defect states and carrier-trapping centers that impede carrier transport and recombination dynamics. Despite the severe irradiation exposure, the ZnGa₂O₄ photodetector preserves ultraviolet photoresponse even at the highest fluence of 10¹³ ions/cm², underscoring its irradiation tolerance. Beyond investigating the robustness of ZnGa₂O₄-based devices, this study establishes swift heavy ion irradiation as a powerful strategy for tailoring defect states and tuning the functional properties of wide-bandgap oxide photodetectors.

DOI：

https://doi.org/10.1016/j.mssp.2026.110948