Vol.:(0123456789) 1 3 Journal of Materials Science: Materials in Electronics https://doi.org/10.1007/s10854-020-03578-2 Inﬂuences of substrate temperature and Ar ﬂow on the properties of RF sputtered Mo thin ﬁlms Kalyan B. Chavan 1,2 · Sachin V. Desarada 1 · Nandu B. Chaure 1 Received: 29 March 2020 / Accepted: 8 May 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract We have reported the inﬂuences of substrate temperature and the rate of Argon (Ar) ﬂow on the properties of Molybdenum (Mo) thin ﬁlms. Diﬀerent Ar ﬂow rates (40, 60, 80, 100 SCCM) and diﬀerent substrate temperatures (30, 100, 200, 300, 400 °C) were used for the substrate of Mo thin ﬁlms by radio frequency (RF) magnetron sputtering technique. Structural properties studied by X-ray diﬀraction technique revealed cubic crystal structure with (110) prominent reﬂection. The elec- trical properties, viz. carrier concentration, resistivity and mobility were studied with the help of Hall measurement system. It has been revealed that substrate temperature and Ar ﬂow signiﬁcantly aﬀect on the thickness, carrier concentration, resis- tivity and mobility of Mo layer. Upon increasing the substrate temperature, thickness increases, whereas thicker samples were grown at 80 and 100 SCCM for temperature 400 °C. The sample grown at 300 °C with 80 SCCM Ar ﬂow measured high carrier concentration, whereas the resistivity and microstrain were found decreased systematically upon increasing the substrate temperature from room temperature 30 °C to 400 °C. Percentage reﬂectance examined with UV–Vis spectrometer revealed the sample grown with 80 SCCM at 400 °C measured higher reﬂectance. Highly dense, compact, uniform, and void-free growth of Mo layer were observed by AFM images. The eﬀect of substrate temperature and Ar ﬂow rate on surface morphology as well as RMS roughness is clearly observed. 1 Introduction To accomplish the universal energy demand with the lim- ited non-renewable resources is one of major challenges of human being. Further, the global climate change, global warming and greenhouse eﬀect are some of the other issues associated with the utilization of non-renewable energy resources. An incremental rate of socio-economic devel- opment demands the excess use of conventional energy sources. Solar energy source is one of the most promising energy sources as it is reliable and abundant. Thin ﬁlm solar cells are widely utilized to harvest the solar energy [1]. Thin ﬁlm solar cells are developed via two conﬁgurations, namely substrate and superstrate solar cells structures. In substrate structure of solar cell, diﬀerent elements are used as a back contact (BC) electrode such as, Ti, Ni, Al, Ag, Au, and Mo [2]. However, Mo has been widely used as BC for CuInSe 2 and CuInGaSe 2 (CIGS) solar cells because of its high ther- mal stability at processing temperature, high reﬂectivity, high electrical conductivity, and low contact resistance [3–5]. Tong et al., investigated the modiﬁcation of Mo BC by Bismuth intermediate layer [6]. Various concentrations of sodium doped in Mo by sputtering technique are used as BC to Cu 2 ZnSnS 4 ﬂexible solar cells by Sun et al. and reported improved eﬃciency ~ 6.2% is for Mo-Mo Na (sandwich) type of BC [7]. By controlling the processing parameters of radio frequency (RF) magnetron sputtering, one can tailor the var- ious structural parameters of Mo layers, such as dislocation density, crystallite size, and texture, which are responsible to the scattering of photo-generated charge carriers [8]. Direct current (DC) and RF sputtering techniques were employed by Zhu and co-worker for the substrate of Mo BC and inves- tigated the inﬂuence of working pressure and target-substrate distance for the development of CIGS solar cells [9]. Chel- vanathan et al. have reported the substrate of Mo thin ﬁlms for diﬀerent operating pressures and RF powers and studied electrical, structural and morphological properties [10]. Fur- thermore, Mo thin ﬁlm has more corrosion resistance, which helps to amplify the life of devices [11]. Good reﬂectance of * Nandu B. Chaure n.chaure@physics.unipune.ac.in 1 Department of Physics, Savitribai Phule Pune University (Formerly University of Pune), Pune 411 007, India 2 Department of Physics, Ahmednagar College, Ahmednagar, Maharashtra, India