Characterization of transparent p-type Cu:ZnS thin films grown by spray pyrolysis technique

Commercial grade p-type transparent conducting Cu doped ZnS thin films with high optical transparency as well as high hole conductivity were grown by industrially beneficial spray pyrolysis method. Pristine ZnS being with wide band gap and high transparency has limited application in optoelectronics due to its low n-type electrical conductivity. To overcome these limitations, ZnS was grown with copper as dopant in +1 state, creating holes to form p-type material. Structural and various spectroscopic studies were conducted to confirm the incorporation of copper and to investigate its chemical state. Analysis has confirmed the formation of Cu:ZnS (CZS) thin films and revealed the formation of Cu:ZnO (CZO) phase along with CuxS related phases in minor fraction. Films with Cu dopant concentration 5 at.% and above have exhibited p-type conductivity. Films with 15 at.% Cu dopant have shown higher electrical conductivity (about 1.37 Scm−1) by retaining about 64% optical transparency at the mid of visible range. [Display omitted] •Cu doped ZnS films were grown by spray pyrolysis technique.•Films with 15 at.% Cu shows good electrical conductivity with 64% transparency.•P-type Cu doped ZnS with 15 at.% Cu is suitable for LED applications.