Vol.:(0123456789) Optical and Quantum Electronics (2019) 51:233 https://doi.org/10.1007/s11082-019-1951-4 1 3 Characterization of CuO/n–Si pn junction synthesized by successive ionic layer adsorption and reaction method Adel H. Omran Alkhayatt 1  · Mustafa D. Jaafer 2  · Hassan Hadi Ali Al Alak 3  · Asala H. Ali 1 Received: 14 April 2019 / Accepted: 22 June 2019 / Published online: 27 June 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Transparent conducting Copper oxide CuO thin flms were successfully synthesized on glass and n-type Silicon substrates by successive ionic layer adsorption and reaction method. The crystal structure, surface texture, optical and electrical properties were stud- ied. The results revealed that the deposited CuO thin flms at diferent cycles number (5, 10, 15), have polycrystalline structure nature with monoclinic phase, and the crystallite size increases with the increase of cycles number. The average roughness and the root mean square values increase with increasing cycles number. The optical energy band gap and Urbach energy was decrement from 2.33 eV and 1.2 eV for 5 cycles to 2.1 eV and 0.82 eV for 15 cycles. The electrical properties of Ni/CuO/n–Si pn junction were studied using current–voltage (I–V) measurements. The barrier heights ( B ) of Ni/CuO/n–Si thin flms were calculated and its values are (0.716, 0.736, 0.723) eV, for 5, 10 and 15 cycles respectively with an applied bias voltage of 3 V. Keywords CuO nanostructure · Thin flms · SILAR method · Surface topography · CuO/n– Si junction 1 Introduction A semiconductors pn junction plays very important roles in the newest of electronic appli- cation technology and in understanding the act mechanism of other semiconductor devices (Sze 2002; Shinde et al. 2018). Copper oxide CuO is one of the most important compo- nents of the metal oxide semiconductor, involving both IB and VIA group elements in the periodic table, where IB and VIA represent group 11 and group 16 of the periodic table of the elements (Gençyılmaz and Taskoprü 2017). P-type, monoclinic structure with narrow band gap (1.2–2.1) eV at room temperature (Sahu et al. 2019; Du et al. 2019). In recent years CuO thin flms attracted scientifc research attention in a wide range of applications * Adel H. Omran Alkhayatt adilh.alkhayat@uokufa.edu.iq 1 Faculty of Science, University of Kufa, Najaf, Iraq 2 Directorate of Education in Al Najaf, Ministry of Education, Najaf, Iraq 3 Faculty of Engineering, University of Kufa, Najaf, Iraq