Efficient antireflective downconversion Er3+ doped ZnO/Si thin film

• ZnO:Er3+ thin films have been successfully deposited on Si substrate using AACVD method.
• The resolved emission spectra of ZnO:Er(2.504 at.%) films, indicate a well incorporation of erbium ions in the host.
• Near-infrared luminescence was detected at 980 nm and 1540 nm useful for solar cell absorbance.
• Low reflectance (16%) and high refraction indexes (1.99) were recorded from 2.504 at.% Er doped ZnO film.

This study is an investigation of the potential of Er doped ZnO thin films for downconversion photons and an antireflective layer when placed in front of the silicon solar cells. We optimized the properties of the film with appropriate deposition conditions on Si (111) substrate by aerosol assisted chemical vapor deposition (AACVD) process. An enhancement of both crystallinity and optical response was achieved in the case of film doped with 2.504 at.% Er3+. A low reflectance and high refractive index of the film were obtained at around 632 nm. Downconversion process was also reached for this film under visible excitation to near-infrared (NIR) 980 nm photons useful for Si solar cell.