Please consider attending the following: MATERIALS ENGINEERING SEMINAR "MOCVD Growth of 1.8 eV Band Gap Zinc Oxide Materials for Solar Cell Applications" By Yang Wang Purdue MSE Preliminary Exam Advisors: Professor Na Lu and Professor Haiyan Wang ABSTRACT Zinc oxide (ZnO) is of great research and application interest as a wide band-gap semiconductor in recent years. It has many desired properties for photovoltaic, thermoelectric and optoelectronic applications, such as large and direct bandgap, high exciton binding energy, earth abundancy, large Seebeck coefficient, high thermal stability, and availability of various nanostructures, nontoxic, etc. This thesis research aims to develop 1.8 eV bandgap semiconductor materials with earth-abundant element Zn using Metal Organic Chemical Vapor Deposition (MOCVD) method. These materials serve as topping layer of a multi-junction solar cell which is a combination of 1.8 eV wide bandgap Schottky solar cell on a 1.1eV band gap Si solar cell to reach high power conversion efficiency at relatively low cost using sustainable and non-toxic materials. Preliminary results show that Ni alloying can tune the bandgap of ZnO in relatively large range. The lowest bandgap achieved in as-grown NiZnO films is 2.0 eV and the band gap is further reduced to 1.83 eV after post annealing. It is expected that the outcome of the work will facilitate the fabrication and manufacture of low-cost wide band gap material with broad band gap tunability for solar cell and other applications. Date: Friday, April 26, 2019 Time: 10:30 A.M. Place: HAMP G212