Fabrication of planar heterojunction oxide solar cells by radio frequency magnetron sputtering

• Published in: Materials letters Vol. 220; pp. 197 - 200
• Main Authors: Vengatesh, P., Karthik kumar, C., Shyju, T.S., Kuppusami, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2018; Elsevier BV
• Subjects: Absorbers; Additive manufacturing; Band gap; Configurations; Copper oxides; Energy conversion efficiency; Energy levels; Heterojunctions; Indium tin oxides; Magnetron sputtering; Materials science; Metal oxides; Nickel oxides; Open circuit voltage; Oxide solar cells; Photovoltaic cells; Power conversion efficiency; Radio frequency; Short circuits; Solar cells; Tin dioxide; Tin oxides; X ray photoelectron spectroscopy; Magnetron sputtering; Voc; Jsc; Power conversion efficiency; η; Oxide solar cells
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2018.03.037

•Oxide solar cells in (n-i-p) and (p-i-n) configurations were fabricated.•2.3% η with Voc 0.75 V and Jsc 5.73 mA/cm2 was achieved for (n-i-p) configuration.•Enhancement in η was attributed to presence of anode interfacial layer (NiO).•0.4% η with decreased Jsc was observed for (p-i-n) configuration. In this study, planar heterojunction oxide solar cells (PHOSC) in both (p-i-n) and (n-i-p) configurations are fabricated using the radio frequency (RF) magnetron sputtered tin oxide (SnO2), copper (II) oxide (CuO) and nickel oxide (NiO) as n-type, absorber and p-type layers, respectively. XRD analysis confirmed the formation of tetragonal SnO2, monoclinic CuO, and cubic NiO phases. The cross-sectional SEM analysis showed the columnar growth for the sputtered metal oxide layers and XPS analysis revealed the valence states of metal oxides. Optical bandgap of n-type, absorber and p-type layers were found to be 3.7, 1.2 and 3.5 eV, respectively which leads to a staircase arrangement in the energy level alignment. The fabricated device with 600 nm thickness shows power conversion efficiency (PCE) (η) of 2.3% with enhanced open-circuit voltage (Voc) = 0.75 V, short-circuit current density (Jsc) = 5.73 mA/cm2 and fill factor (FF) of about 54% for (n-i-p) configuration. Similarly for (p-i-n) configuration, (η) of 0.4% is achieved with decreased Jsc. This new strategy paves the way for easier, stable and large scale fabrication of planar oxide solar cells.