title: Optical properties of ZnO/ZnS and ZnO/ZnTe heterostructures for photovoltaic applications.
abstract: Although ZnO and ZnS are abundant, stable, and environmentally benign, their band gap energies (3.44, 3.72 eV, respectively) are too large for optimal photovoltaic efficiency. By using band-corrected pseudopotential density functional theory calculations, we study how the band gap, optical absorption, and carrier localization can be controlled by forming quantum-well-like and nanowire-based heterostructures of ZnO/ZnS and ZnO/ZnTe. In the case of ZnO/ZnS core/shell nanowires, which can be synthesized using existing methods, we obtain a band gap of 2.07 eV, which corresponds to a Shockley-Quiesser efficiency limit of 23%. On the basis of these nanowire results, we propose that ZnO/ZnS core/shell nanowires can be used as photovoltaic devices with organic polymer semiconductors as p-channel contacts.
authors.affiliation: Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. jschrier@lbl.gov
authors.forename: Joshua
authors.initials: J
authors.lastname: Schrier
authors.forename: Denis O
authors.initials: DO
authors.lastname: Demchenko
authors.forename: Lin-Wang
authors.initials: LW
authors.lastname: Wang
authors.forename: A Paul
authors.initials: AP
authors.lastname: Alivisatos
mesh_terms: D003198:Computer Simulation; D011211:Electric Power Supplies; D004574:Electromagnetic Fields; D008027:Light; D008956:Models, Chemical; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D010777:Photochemistry / Q000379:methods*; D012666:Semiconductors; D013691:Tellurium / Q000737:chemistry* / Q000528:radiation effects; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D013691:Tellurium; D015034:Zinc Oxide