Invited) Sputtered Metal Oxide Broken Gap Junctions

Broken gap metal oxide tunnel junctions have been created by sputtering. Using a ceramic ZnO-SnO2 target and a reactively sputtered copper target we deposited ZnSnO3 and Cu2O for the n-type and p-type layers, respectively. AlCuO2 can also be used for the p-type layer. It shows better thermal uniformity and improved optical transmittance, but somewhat higher specific junction resistance. The band structure of the respective materials have theoretical work functions which line up with the band structure for a tandem solar cell and quantum dot LED applications. As-deposited films demonstrated a dependence of the I-V profile with post-deposition rapid thermal anneal. Total junction specific contact resistances under 1 ohm-cm2 have been achieved.