The impact of intrinsic point defects on the optoelectronic functionality of CuGaO2: insights from first-principles calculations

Abstract

The conversion of light energy into electrical or chemical energy is essential for sustainable development and clean energy applications, making optoelectronic functional technology a critical field of study. Among optoelectronic materials, delafossite CuGaO₂ stands out due to its unique p-type conductivity and optoelectronic characteristics. However, the effect of intrinsic point defects within its lattice structure on the optoelectronic performance remains not fully comprehended. This study presents a systematic analysis of the thermodynamic stability, electronic structure, and optical properties of intrinsic point defects in CuGaO₂, and their impact on optoelectronic functionality, utilizing first-principles calculations. The findings reveal that copper vacancies (V_Cu), copper–gallium antisites (Cu_Ga), and interstitial oxygen (O_i) are the predominant intrinsic point defects. These defects introduce new energy levels within the bandgap, significantly enhancing the light absorption spectrum and, consequently, the optoelectronic performance of CuGaO₂. This research extends prior studies by identifying the types and concentrations of intrinsic point defects in CuGaO₂ and their regulatory effect on optoelectronic performance, and by proposing novel strategies for the design and optimization of CuGaO₂-based optoelectronic materials. The results are significant for advancing the understanding of CuGaO₂ and providing valuable insights for defect engineering in other optoelectronic materials. This study underscores the significance of precise control over intrinsic point defects at the atomic level for the development of high-performance optoelectronic materials, thus opening new avenues for the advancement of future optoelectronic technologies.