Control of Ge-Homojunction Band Offsets Via Ultrathin Ga-as Dipole Layers
Band offsets of 0.35-0.45 eV are produced at Ge homojunctions by placing a monolayer of As and an adjacent monolayer of Ga between the two Ge bulks. The "Ga-first" and "As-first" growth sequences exhibit band offsets of similar magnitude but opposite sign, consistent with a truly dipolar effect. To our knowledge, this is the first time that intralayer control of band discontinuities is extended to homojunctions, thereby expanding the potential domain of band offset engineering. The offsets were measured with photoemission spectroscopy. The existence, sign, and approximate magnitude of the effect are correctly predicted by a "theoretical alchemy" model.
Univ wisconsin,ctr synchrotron radiat,madison,wi 53706. univ wisconsin,dept phys,madison,wi 53706. ecole polytech fed lausanne,inst phys appli,ch-1015 lausanne,switzerland. scuola int super studi avanzati,i-34013 trieste,italy. Mckinley, jt, forschungszentrum julich gmbh,inst thin film & ion technol,pob 1913,w-5170 julich,germany.
ISI Document Delivery No.: HM078
Record created on 2006-10-03, modified on 2016-08-08