Characterization of Intrinsic and Doped ZnO Thin-Films Deposited by RF Magnetron Sputtering for Chalcogenide Based Solar Cell Applications

In high performance chalcogenide based thin-film solar cells, a bilayer intrinsic and doped zinc-oxide (ZnO) n-type stacks are used as window layer. Intrinsic ZnO and aluminum-doped ZnO thin-films were deposited on soda lime glass substrates using the standard recipe by radio-frequency (RF) magnetron sputtering with thickness 80 nm and 350 nm respectively. The structural, optical and electrical properties of the as deposited thin-films were studied by various characterization techniques such as X-Ray Diffractometry (XRD), UV-Vis spectroscopy and Hall-effect measurements. It was found from structural studies that both films are crystallographically oriented along (002) and (103) planes with hexagonal Wurtzite type. The optical transmittances and bandgaps were found around 90% (in visible and near infrared regions of spectrum) and 3.28 eV respectively. According to our findings, it is concluded that these as deposited films are suitable as window layer for promising chalcogenide Copper zinc tin sulphide (Cu
₂
ZnSnS
₄
, CZTS) based thin-film solar cells.