Indium doped Cd1-xZnxO alloys as wide window transparent conductors

•Indium doped Cd1-xZnxO alloys across the full composition range were synthesized.•Alloys change from rocksalt (RS) to wurtzite (WZ) when x is higher than 30%.•RS-Cd1-xZnxO phase can be doped with In as efficiently as CdO, achieving a low resistivity ~ 2.0 × 10− 4 Ω-cm.•Wide transparency window from 380 to 1200 nm•In doped CdO transmits more solar photons than commercial fluorine doped tin oxide.

We have synthesized Indium doped Cd1-xZnxO alloys across the full composition range using magnetron sputtering method. The crystallographic structure of these alloys changes from rocksalt (RS) to wurtzite (WZ) when the Zn content is higher than 30%. The rocksalt phase alloys in the composition range 0 < x < 0.3 can be efficiently n-type doped, shifting the absorption edge to 3.25 eV and reducing resistivity to about 2.0 × 10− 4 Ω-cm. We found that In doped CdO (ICO) transmits more solar photons than commercial fluorine doped tin oxide (FTO) with comparable sheet conductivity. The infrared transmittance is further extended to longer than 1500 nm wavelengths by depositing the In doped Cd1-xZnxO in ~ 1% of O2. This material has a potential for applications as a transparent conductor for silicon and multi-junction solar cells.