Optical properties of ZnO/ZnS and ZnO/ZnTe heterostructures for photovoltaic applications.
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.
Schrier
Joshua
J
Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. jschrier@lbl.gov
Demchenko
Denis O
DO
Wang
Lin-Wang
LW
Alivisatos
A Paul
AP
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
D013691:Tellurium; D015034:Zinc Oxide