Nano Letters · 2011 · 284 citations · 21 references
Natural SciencesMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsPhotovoltaic MaterialsQuantum DotsSemiconductor InterfacesSemiconductor PhysicsSolar Cell MaterialsSolar CellsBack Contact MaterialsCarrier Transport MechanismsN-type Oxide SemiconductorsQuantum Dot Solar CellsSemiconductor Quantum DotsTransition Metal OxidesValence BandValence Band Structure
The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoO(x)) and vanadium oxide (V(2)O(x)) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoO(x) HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoO(x) and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoO(x). The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoO(x) layer.
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Efficient inverted polymer solar cells
Gang Li, Chih‐Wei Chu, Vishal Shrotriya et al. · Applied Physics Letters · 2006 · 780 citations
Natural Sciences, Materials Engineering, Materials Science +17