Investigations Into the Role of Native Defects on Photovoltaic and Spintronic Properties in Copper Oxide

Abstract

CuO is a promising contender for photovoltaics, photodetection, photocatalysis, and spintronics in theory, but experimental success in terms of device performance has been limited. We used experimental and theoretical techniques to examine the fascinating optoelectronic and spintronic features of a p-type semiconductor; i.e. copper oxide. Absorption spectra of CuO have revealed intriguing properties such as defect-induced strong absorption in the visible and near-infrared (NIR) regions, making it an attractive candidate for NIR and broadband detection. Additionally, due to its antiferromagnetic characteristics, CuO has potential applications in spintronics. Clearly, these applicability ranges are greatly dependent on the intrinsic material qualities and defects. To gain a better understanding of CuO band structures, defect dynamics, charge distribution, and absorption properties; ab-initio calculations were conducted in a systematic manner. Additionally, the stability of several types of defects has been investigated theoretically in Cu and O-rich environments. The literature is ambiguous about the stability of several defects in CuO, including copper vacancies, oxygen vacancies, and interstitials. Interestingly, it is discovered that V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Cu</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</sub> di-vacancies and V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</sub> are extremely stable in O-deficient environments, whereas V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Cu</sub> is highly stable in O-rich environments. Numerous defects such as copper vacancies, oxygen vacancies, and di-vacancies all contribute significantly to the photovoltaic features such as quantum-efficiency. Furthermore, unlike pristine CuO, defect assisted CuO has a significant magnetic moment as shown by first-principle calculations, making it a suitable option for spintronics. The work will open several features of CuO for next generation devices.