Abstract
In this paper, molybdenum (Mo) thin films are deposited on soda-lime glass (SLG) substrates by direct current magnetron sputtering and heated in three different modes at different temperatures, including substrate heating, annealing treatment, and both substrate heating and annealing treatment. The effects of heating temperature and heating mode on the structures, morphology, optical and electrical properties of Mo thin films were systematically investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), atomic force microscope (AFM) and UV-visible spectrophotometer (UV-vis spectra). It is shown that as the substrate and annealing temperature increase, the crystallinity of Mo thin films is improved, and the grain sizes become bigger. Especially in the mode of both substrate heating and annealing treatment at higher temperature, the obtained Mo thin films show higher crystallinity and conductivity. Moreover, with the increase of substrate and annealing temperature in different heating modes, both the surface compactness of Mo films and the optical reflectance increase correspondingly. Furthermore, the Mo film, prepared at the substrate heating temperature of 400 °C and annealed at 400 °C, showed excellent comprehensive performance, and the resistivity is as low as 1.36 × 10−5 Ω·cm. Using this optimized Mo thin film as an electrode, copper indium gallium selenium (CIGS) solar cells have a maximum photo-conversion efficiency of 12.8%.
Highlights
Molybdenum (Mo) thin film obtained by sputtering method has been the primary choice as the back contact material for thin film solar cells, such as the Cu(In,Ga)Se2 (CIGS)-based solar cell.this is a copper indium gallium selenide thin-film solar cell (or copper indium gallium selenium (CIGS) cell, sometimesCI(G)S or CIS cell) used to convert sunlight into electric power
The preparation of Mo thin films includes two processes: direct current (DC) magnetron sputtering at different substrate temperatures and subsequent vacuum annealing at different temperatures in a tube furnace
Mo thin films are prepared on soda-lime glass substrates by DC magnetron sputtering and heating in different modes at different temperatures, including substrate heating, annealing treatment, and both substrate heating and annealing treatment
Summary
Molybdenum (Mo) thin film obtained by sputtering method has been the primary choice as the back contact material for thin film solar cells, such as the Cu(In,Ga)Se2 (CIGS)-based solar cell.this is a copper indium gallium selenide thin-film solar cell (or CIGS cell, sometimesCI(G)S or CIS cell) used to convert sunlight into electric power. Mo thin films can affect the out-diffusion of sodium from soda lime glass (SLG) substrates [3,4,5] These make Mo a primary choice as a back-contact material, for the common CIGS material, and for the industry standard for novel and selenium-free absorber layers, such as Cu2 ZnSnS4 (CZTS), CuSnS3 (CTS) and SnS [6,7,8]. The properties and microstructures of Mo thin films could be controlled and adjusted to promote the functionality of solar cells in industry [9] and their morphology can be obviously changed from dense to porous, depending on the processing parameters, such as the sputtering pressure, sputtering power, substrate temperature, annealing temperature, substrate-target distance and type of discharge [10,11,12,13] These in turn affect the residual stress, conductivity, optical reflectance and adhesion with soda-lime glass (SLG) [14]. To the best our knowledge, the effects of two heating modes and heating temperature on the microstructures and properties of Mo film have never been compared and investigated systematically
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
