Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with gre... more Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with great potential in low-cost photovoltaics (PV) applications. Cu2O is a versatile p-type oxide that absorbs visible light and can be solution-processed at low temperatures. ZnO is a wide-Eg n-type material with good electronic properties and has already been widely incorporated into other low-cost PV technologies such as organic and dye-sensitized solar cells. While ZnO/Cu2O devices have large theoretical efficiencies (as high as 20%) [1], practical devices do not reach their full potential due to poor charge collection and recombination. ZnO/Cu2O PV's can be improved by optimizing deposition conditions, such as solution pH and temperature, and device geometry, such as layer thickness [2]. This talk, however, will discuss how semiconducting polymer layers can further enhance performance for scalable device fabrication. In particular, polymer type and the Cu2O/polymer interface will be di...
Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with gre... more Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with great potential in low-cost photovoltaics (PV) applications. Cu2O is a versatile p-type oxide that absorbs visible light and can be solution-processed at low temperatures. ZnO is a wide-Eg n-type material with good electronic properties and has already been widely incorporated into other low-cost PV technologies such as
Electrochemical deposition and Atmospheric Atomic Layer Deposition (AALD) are high-throughput, sc... more Electrochemical deposition and Atmospheric Atomic Layer Deposition (AALD) are high-throughput, scalable methods that can be used to produce low-cost transition metal oxides for photovoltaic devices. Previous work by our group has used electrochemical deposition to fabricate ZnO/Cu2O cells, however the performance of these cells is limited by poor Cu2O transport properties and recombination at interface states. AALD has been shown
ABSTRACT Using thermal co-evaporation we have prepared epitaxial Cu2ZnSnS4 (CZTS) films on Si(001... more ABSTRACT Using thermal co-evaporation we have prepared epitaxial Cu2ZnSnS4 (CZTS) films on Si(001) substrates. A substrate temperature as high as 370 °C and proper substrate cleaning (HF-dip followed by thermal desorption of surface hydrogens) are found to be necessary for the epitaxial growth. Detailed transmission electron microscopy measurements and X-ray diffraction studies are used to reveal the orientation relation of the CZTS films with the underlying silicon substrate, and the formation of defects within the CZTS layer.
Large-area free-standing arrays of TiO(2) nanorods and nanotubes were selectively synthesized on ... more Large-area free-standing arrays of TiO(2) nanorods and nanotubes were selectively synthesized on transparent conducting indium tin oxide substrates using sol-gel electrophoresis and anodic alumina (AAO) thin film templates. The effect of sol-gel ageing on the growth of TiO(2) was explained, providing a tailored ability to produce nanotubes and nanorods. An annular tungsten base electrode, stemming from the anodization of the AAO template, was found to be crucial to the growth of nanotubes. This was supported by a study of substrate annealing in a reducing atmosphere. The work can be readily adapted for the fabrication of free-standing arrays of other metal, metal oxide, and complex oxide nanorod and nanotube arrays on conducting substrates.
Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with gre... more Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with great potential in low-cost photovoltaics (PV) applications. Cu2O is a versatile p-type oxide that absorbs visible light and can be solution-processed at low temperatures. ZnO is a wide-Eg n-type material with good electronic properties and has already been widely incorporated into other low-cost PV technologies such as organic and dye-sensitized solar cells. While ZnO/Cu2O devices have large theoretical efficiencies (as high as 20%) [1], practical devices do not reach their full potential due to poor charge collection and recombination. ZnO/Cu2O PV's can be improved by optimizing deposition conditions, such as solution pH and temperature, and device geometry, such as layer thickness [2]. This talk, however, will discuss how semiconducting polymer layers can further enhance performance for scalable device fabrication. In particular, polymer type and the Cu2O/polymer interface will be di...
Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with gre... more Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with great potential in low-cost photovoltaics (PV) applications. Cu2O is a versatile p-type oxide that absorbs visible light and can be solution-processed at low temperatures. ZnO is a wide-Eg n-type material with good electronic properties and has already been widely incorporated into other low-cost PV technologies such as
Electrochemical deposition and Atmospheric Atomic Layer Deposition (AALD) are high-throughput, sc... more Electrochemical deposition and Atmospheric Atomic Layer Deposition (AALD) are high-throughput, scalable methods that can be used to produce low-cost transition metal oxides for photovoltaic devices. Previous work by our group has used electrochemical deposition to fabricate ZnO/Cu2O cells, however the performance of these cells is limited by poor Cu2O transport properties and recombination at interface states. AALD has been shown
ABSTRACT Using thermal co-evaporation we have prepared epitaxial Cu2ZnSnS4 (CZTS) films on Si(001... more ABSTRACT Using thermal co-evaporation we have prepared epitaxial Cu2ZnSnS4 (CZTS) films on Si(001) substrates. A substrate temperature as high as 370 °C and proper substrate cleaning (HF-dip followed by thermal desorption of surface hydrogens) are found to be necessary for the epitaxial growth. Detailed transmission electron microscopy measurements and X-ray diffraction studies are used to reveal the orientation relation of the CZTS films with the underlying silicon substrate, and the formation of defects within the CZTS layer.
Large-area free-standing arrays of TiO(2) nanorods and nanotubes were selectively synthesized on ... more Large-area free-standing arrays of TiO(2) nanorods and nanotubes were selectively synthesized on transparent conducting indium tin oxide substrates using sol-gel electrophoresis and anodic alumina (AAO) thin film templates. The effect of sol-gel ageing on the growth of TiO(2) was explained, providing a tailored ability to produce nanotubes and nanorods. An annular tungsten base electrode, stemming from the anodization of the AAO template, was found to be crucial to the growth of nanotubes. This was supported by a study of substrate annealing in a reducing atmosphere. The work can be readily adapted for the fabrication of free-standing arrays of other metal, metal oxide, and complex oxide nanorod and nanotube arrays on conducting substrates.
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