Talia Gershon - Academia.edu (original) (raw)

Papers by Talia Gershon

Research paper thumbnail of Metal oxide applications in organic-based photovoltaics

Organic-based photovoltaics (PV) have attracted increasing attention in recent years and efficien... more Organic-based photovoltaics (PV) have attracted increasing attention in recent years and efficiencies exceeding 8% have recently been confirmed. These low cost, lightweight and mechanically flexible devices offer unique advantages and opportunities currently unavailable with crystalline silicon technology. Progress in the field of organic PV has been achieved in part due to the incorporation of transition metal oxides. These offer a wide range of optical and electronic properties, making them applicable in organic-based PV in many capacities. Transparent electrodes can be made from doped metal oxides. The high intrinsic charge carrier mobility of many undoped metal oxides makes them attractive as active materials and charge collectors. Metal oxides can increase the charge selectivity of the electrodes due to the energetic positioning of their valence and conduction bands. Thin films of these materials can manipulate the light distribution inside of organic devices, allowing for improved light harvesting. Metal oxides are stable and can be processed at low temperatures. Consequently, they have been demonstrated as suitable intermediate layer materials in tandem cells. Finally, oxygen-deficient metal oxides can improve the stability of the oxygensensitive organic semiconductors. The present work reviews the various applications of metal oxide layers in organic PV devices and summarises the challenges associated with organic/ oxide interfaces.

Research paper thumbnail of Atomic-Scale Observation of Oxygen Substitution and Its Correlation with Hole-Transport Barriers in Cu 2 ZnSnSe 4 Thin-Film Solar Cells

Advanced Energy Materials, 2016

Research paper thumbnail of Flexible kesterite solar cells on ceramic substrates for advanced thermal processing

2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), 2015

Research paper thumbnail of Protective insulating layer and chemical mechanical polishing for polycrystalline thin film solar cells

Research paper thumbnail of The Role of Sodium as a Surfactant and Suppressor of Non-Radiative Recombination at Internal Surfaces in Cu 2 ZnSnS 4

Advanced Energy Materials, 2014

Research paper thumbnail of Capturing the effect of long low-temperature anneals on the sub-bandgap defect structure of CZTSSe

Carbon Nanotubes, Graphene, and Emerging 2D Materials for Electronic and Photonic Devices VIII, 2015

Research paper thumbnail of The impact of sodium on the sub-bandgap states in CZTSe and CZTS

Applied Physics Letters, 2015

Research paper thumbnail of Monolithic Perovskite-CIGS Tandem Solar Cells via In Situ Band Gap Engineering

Advanced Energy Materials, 2015

Research paper thumbnail of CZTS-Based Thin-Film Solar Cells Prepared via Coevaporation

Ito/Copper Zinc Tin Sulfide-Based Thin-Film Solar Cells, 2014

Research paper thumbnail of Chemical Consequences of Alkali Inhomogeneity in Cu 2 ZnSnS 4 Thin-Film Solar Cells

Advanced Energy Materials, 2015

Research paper thumbnail of Effect of Thin Polymer Layers on the Performance of ZnO/Cu2O Solar Cells

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...

Research paper thumbnail of Perovskite-kesterite monolithic tandem solar cells with high open-circuit voltage

Applied Physics Letters, 2014

Research paper thumbnail of Effect of Thin Polymer Layers on the Performance of ZnO/Cu2O Solar Cells

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

Research paper thumbnail of Understanding the relationship between Cu2ZnSn(S,Se)4 material properties and device performance

MRS Communications, 2014

Cu 2 ZnSn(S,Se) 4 (CZTSSe) photovoltaics (PV) have long been considered promising candidates for ... more Cu 2 ZnSn(S,Se) 4 (CZTSSe) photovoltaics (PV) have long been considered promising candidates for large-scale PV deployment due to the availability of constituent elements and steady improvements in device efficiency over time. The key limitation to high efficiency in this technology remains a deficit in the open-circuit voltage with respect to the band gap. The past decade has seen significant progress toward understanding how the various material properties such as bulk and surface composition, point defects (intrinsic and extrinsic), and grain boundaries all impact the optoelectronic properties of CZTSSe materials, and consequently device performance. This paper aims to summarize what is known about the CZTSSe bulk and surfaces, and how these material properties may be related to the Voc deficit.

Research paper thumbnail of Interface Defect States and Charge Transport Properties in Low-Cost Photovoltaic Devices made from Scalable Deposition Methods

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

Research paper thumbnail of Cu 2 ZnSnSe 4 Thin-Film Solar Cells by Thermal Co-evaporation with 11.6% Efficiency and Improved Minority Carrier Diffusion Length

Advanced Energy Materials, 2014

Research paper thumbnail of Epitaxial growth of kesterite Cu2ZnSnS4 on a Si(001) substrate by thermal co-evaporation

Thin Solid Films, 2014

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.

Research paper thumbnail of Improved fill factors in solution-processed ZnO/Cu2O photovoltaics

Thin Solid Films, 2013

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

Research paper thumbnail of Thin-film ZnO/Cu2O solar cells incorporating an organic buffer layer

Solar Energy Materials and Solar Cells, 2012

This work presents a novel approach to overcoming the limitations of low long-wavelength absorpti... more This work presents a novel approach to overcoming the limitations of low long-wavelength absorption and short charge transport lengths in electrodeposited bilayer ZnO/Cu 2 O solar cells. Here we reduce the Cu 2 O thickness to approximately the minority carrier transport length and coat a film of a semiconducting polymer between the Cu 2 O and a top electrode. We demonstrate efficient holeinjection from Cu 2 O into the semiconducting polymer as well as blocking of electrons by the polymer. We also show optical confinement of long-wavelength light inside of the collection area in the Cu 2 O resulting from refractive index mismatch between the polymer and Cu 2 O. This leads to improved extraction of charge carriers and higher J sc values from much thinner Cu 2 O layers than are normally used.

Research paper thumbnail of The selective fabrication of large-area highly ordered TiO 2 nanorod and nanotube arrays on conductive transparent substrates via sol–gel electrophoresis

Nanotechnology, 2009

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.

Research paper thumbnail of Metal oxide applications in organic-based photovoltaics

Organic-based photovoltaics (PV) have attracted increasing attention in recent years and efficien... more Organic-based photovoltaics (PV) have attracted increasing attention in recent years and efficiencies exceeding 8% have recently been confirmed. These low cost, lightweight and mechanically flexible devices offer unique advantages and opportunities currently unavailable with crystalline silicon technology. Progress in the field of organic PV has been achieved in part due to the incorporation of transition metal oxides. These offer a wide range of optical and electronic properties, making them applicable in organic-based PV in many capacities. Transparent electrodes can be made from doped metal oxides. The high intrinsic charge carrier mobility of many undoped metal oxides makes them attractive as active materials and charge collectors. Metal oxides can increase the charge selectivity of the electrodes due to the energetic positioning of their valence and conduction bands. Thin films of these materials can manipulate the light distribution inside of organic devices, allowing for improved light harvesting. Metal oxides are stable and can be processed at low temperatures. Consequently, they have been demonstrated as suitable intermediate layer materials in tandem cells. Finally, oxygen-deficient metal oxides can improve the stability of the oxygensensitive organic semiconductors. The present work reviews the various applications of metal oxide layers in organic PV devices and summarises the challenges associated with organic/ oxide interfaces.

Research paper thumbnail of Atomic-Scale Observation of Oxygen Substitution and Its Correlation with Hole-Transport Barriers in Cu 2 ZnSnSe 4 Thin-Film Solar Cells

Advanced Energy Materials, 2016

Research paper thumbnail of Flexible kesterite solar cells on ceramic substrates for advanced thermal processing

2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), 2015

Research paper thumbnail of Protective insulating layer and chemical mechanical polishing for polycrystalline thin film solar cells

Research paper thumbnail of The Role of Sodium as a Surfactant and Suppressor of Non-Radiative Recombination at Internal Surfaces in Cu 2 ZnSnS 4

Advanced Energy Materials, 2014

Research paper thumbnail of Capturing the effect of long low-temperature anneals on the sub-bandgap defect structure of CZTSSe

Carbon Nanotubes, Graphene, and Emerging 2D Materials for Electronic and Photonic Devices VIII, 2015

Research paper thumbnail of The impact of sodium on the sub-bandgap states in CZTSe and CZTS

Applied Physics Letters, 2015

Research paper thumbnail of Monolithic Perovskite-CIGS Tandem Solar Cells via In Situ Band Gap Engineering

Advanced Energy Materials, 2015

Research paper thumbnail of CZTS-Based Thin-Film Solar Cells Prepared via Coevaporation

Ito/Copper Zinc Tin Sulfide-Based Thin-Film Solar Cells, 2014

Research paper thumbnail of Chemical Consequences of Alkali Inhomogeneity in Cu 2 ZnSnS 4 Thin-Film Solar Cells

Advanced Energy Materials, 2015

Research paper thumbnail of Effect of Thin Polymer Layers on the Performance of ZnO/Cu2O Solar Cells

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...

Research paper thumbnail of Perovskite-kesterite monolithic tandem solar cells with high open-circuit voltage

Applied Physics Letters, 2014

Research paper thumbnail of Effect of Thin Polymer Layers on the Performance of ZnO/Cu2O Solar Cells

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

Research paper thumbnail of Understanding the relationship between Cu2ZnSn(S,Se)4 material properties and device performance

MRS Communications, 2014

Cu 2 ZnSn(S,Se) 4 (CZTSSe) photovoltaics (PV) have long been considered promising candidates for ... more Cu 2 ZnSn(S,Se) 4 (CZTSSe) photovoltaics (PV) have long been considered promising candidates for large-scale PV deployment due to the availability of constituent elements and steady improvements in device efficiency over time. The key limitation to high efficiency in this technology remains a deficit in the open-circuit voltage with respect to the band gap. The past decade has seen significant progress toward understanding how the various material properties such as bulk and surface composition, point defects (intrinsic and extrinsic), and grain boundaries all impact the optoelectronic properties of CZTSSe materials, and consequently device performance. This paper aims to summarize what is known about the CZTSSe bulk and surfaces, and how these material properties may be related to the Voc deficit.

Research paper thumbnail of Interface Defect States and Charge Transport Properties in Low-Cost Photovoltaic Devices made from Scalable Deposition Methods

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

Research paper thumbnail of Cu 2 ZnSnSe 4 Thin-Film Solar Cells by Thermal Co-evaporation with 11.6% Efficiency and Improved Minority Carrier Diffusion Length

Advanced Energy Materials, 2014

Research paper thumbnail of Epitaxial growth of kesterite Cu2ZnSnS4 on a Si(001) substrate by thermal co-evaporation

Thin Solid Films, 2014

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.

Research paper thumbnail of Improved fill factors in solution-processed ZnO/Cu2O photovoltaics

Thin Solid Films, 2013

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

Research paper thumbnail of Thin-film ZnO/Cu2O solar cells incorporating an organic buffer layer

Solar Energy Materials and Solar Cells, 2012

This work presents a novel approach to overcoming the limitations of low long-wavelength absorpti... more This work presents a novel approach to overcoming the limitations of low long-wavelength absorption and short charge transport lengths in electrodeposited bilayer ZnO/Cu 2 O solar cells. Here we reduce the Cu 2 O thickness to approximately the minority carrier transport length and coat a film of a semiconducting polymer between the Cu 2 O and a top electrode. We demonstrate efficient holeinjection from Cu 2 O into the semiconducting polymer as well as blocking of electrons by the polymer. We also show optical confinement of long-wavelength light inside of the collection area in the Cu 2 O resulting from refractive index mismatch between the polymer and Cu 2 O. This leads to improved extraction of charge carriers and higher J sc values from much thinner Cu 2 O layers than are normally used.

Research paper thumbnail of The selective fabrication of large-area highly ordered TiO 2 nanorod and nanotube arrays on conductive transparent substrates via sol–gel electrophoresis

Nanotechnology, 2009

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.