Philipp Löper
YOU?
Author Swipe
View article: Efficient upconversion systems for silicon solar cells
Efficient upconversion systems for silicon solar cells Open
Frequency upconversion of sub-bandgap photons is one approach to push the efficiency limit of solar cells with one bandgap. A highly efficient upconversion system is Erbium doped NaYF4. In this paper we present photoluminescence studies on…
View article: Nanoscale Study of the Hole-Selective Passivating Contacts with High Thermal Budget Using C-AFM Tomography
Nanoscale Study of the Hole-Selective Passivating Contacts with High Thermal Budget Using C-AFM Tomography Open
We investigate hole-selective passivating contacts that consist of an interfacial layer of silicon oxide (SiOx) and a layer of boron-doped SiCx(p). The fabrication process of these contacts involves an annealing step at temperatures above …
View article: remUCPS - rate equation model of upconversion dynamics including photonic structure effects
remUCPS - rate equation model of upconversion dynamics including photonic structure effects Open
The remUCPS library provides an object-oriented implementation of a rate equation model, describing the upconversion dynamics in the upconverter Erbium in the host crystal NaYF4. Additonally, the model features the effects of a photonic st…
View article: A Mixed-Phase SiO<sub>x</sub> Hole Selective Junction Compatible With High Temperatures Used in Industrial Solar Cell Manufacturing
A Mixed-Phase SiO<sub>x</sub> Hole Selective Junction Compatible With High Temperatures Used in Industrial Solar Cell Manufacturing Open
We present a p-type passivating rear contact that complies with integration into standard solar cell manufacturing with phosphorus-diffused front side. Our contact structure consists of a thin SiOx tunneling layer grown by wet chemistry an…
View article: Phosphorous-Doped Silicon Carbide as Front-Side Full-Area Passivating Contact for Double-Side Contacted c-Si Solar Cells
Phosphorous-Doped Silicon Carbide as Front-Side Full-Area Passivating Contact for Double-Side Contacted c-Si Solar Cells Open
We present an electron selective passivating contact based on a tunneling SiOx capped with a phosphorous doped siliconcarbideandpreparedwithahigh-temperaturethermalanneal. We investigate in detail the effects of the preparation conditions …
View article: Crystalline Silicon Solar Cells With Coannealed Electron- and Hole-Selective SiC<i> <sub>x</sub> </i> Passivating Contacts
Crystalline Silicon Solar Cells With Coannealed Electron- and Hole-Selective SiC<i> <sub>x</sub> </i> Passivating Contacts Open
We present electron- and hole-selective passivating contacts based on wet-chemically grown interfacial SiOx and overlying in-situ doped silicon carbide (SiCx) deposited by plasma-enhanced chemical vapor deposition. After annealing at 850 d…
View article: Measuring carrier injection from amorphous silicon into crystalline silicon using photoluminescence
Measuring carrier injection from amorphous silicon into crystalline silicon using photoluminescence Open
In devices with intrinsic amorphous silicon layer on a crystalline silicon substrate, the light absorbed in the amorphous layer can be weakly electronically coupled into the silicon base. Such carrier injection has previously been reported…
View article: Carrier injection from amorphous silicon into crystalline silicon determined with photoluminescence
Carrier injection from amorphous silicon into crystalline silicon determined with photoluminescence Open
Intrinsic amorphous silicon provides excellent surface passivation on crystalline silicon. It has previously been shown, that carriers that are photo generated in the amorphous silicon can be efficiently electronically injected into the cr…
View article: Complex Refractive Indices of Cesium–Formamidinium-Based Mixed-Halide Perovskites with Optical Band Gaps from 1.5 to 1.8 eV
Complex Refractive Indices of Cesium–Formamidinium-Based Mixed-Halide Perovskites with Optical Band Gaps from 1.5 to 1.8 eV Open
Cesium-formamidinium-based mixed-halide perovskite materials with optical band gaps ranging from 1.5 to 1.8 eV are investigated by variable-angle spectroscopic ellipsometry. The determined complex refractive indices are shown to depend on …
View article: Toward Annealing‐Stable Molybdenum‐Oxide‐Based Hole‐Selective Contacts For Silicon Photovoltaics
Toward Annealing‐Stable Molybdenum‐Oxide‐Based Hole‐Selective Contacts For Silicon Photovoltaics Open
Molybdenum oxide (MoO X ) combines a high work function with broadband optical transparency. Sandwiched between a hydrogenated intrinsic amorphous silicon passivation layer and a transparent conductive oxide, this material allows a highly …
View article: Hole-Collection Mechanism in Passivating Metal-Oxide Contacts on Si Solar Cells: Insights From Numerical Simulations
Hole-Collection Mechanism in Passivating Metal-Oxide Contacts on Si Solar Cells: Insights From Numerical Simulations Open
Silicon heterojunction solar cells enable high conversion efficiencies, thanks to their passivating contacts which consist of layered stacks of intrinsic and doped amorphous silicon. However, such contacts may reduce the photo current, whe…
View article: Recombination Analysis of Phosphorus-Doped Nanostructured Silicon Oxide Passivating Electron Contacts for Silicon Solar Cells
Recombination Analysis of Phosphorus-Doped Nanostructured Silicon Oxide Passivating Electron Contacts for Silicon Solar Cells Open
We analyze the recombination properties of passivating electron selective contacts based on nanostructured silicon oxide. Our contact design is based on an interfacial buffer oxide capped with a bilayer structure of phosphorus-doped silico…
View article: Numerical simulation of temperature dependence of MoOx based SHJ solar cell
Numerical simulation of temperature dependence of MoOx based SHJ solar cell Open
Transition metal oxides based high efficiency silicon heterojunction (SHJ) solar cells have emerged as promising candidate due to their low manufacturing cost and avoidance of poisonous dopant gases. Temperature dependent J V curves in suc…
View article: Moox And Wox Based Hole-Selective Contacts For Wafer-Based Si Solar Cells
Moox And Wox Based Hole-Selective Contacts For Wafer-Based Si Solar Cells Open
Highly-transparent carrier-selective front contacts open a pathway towards entirely dopant free Si solar cells. Hole selective a-Si:H/MoOx/ITO front contact stacks were already successfully applied in such novel devices. However, for optim…
View article: Photocurrent Spectroscopy of Perovskite Layers and Solar Cells: A Sensitive Probe of Material Degradation
Photocurrent Spectroscopy of Perovskite Layers and Solar Cells: A Sensitive Probe of Material Degradation Open
Optical absorptance spectroscopy of polycrystalline CH3NH3PbI3 films usually indicates the presence of a PbI2 phase, either as a preparation residue or due to film degradation, but gives no insight on how this may affect electrical propert…
View article: Efficient Carrier Injection from Amorphous Silicon into Crystalline Silicon Determined from Photoluminescence
Efficient Carrier Injection from Amorphous Silicon into Crystalline Silicon Determined from Photoluminescence Open
For devices with intrinsic amorphous silicon layer on a crystalline silicon substrate, the light absorbed in the amorphous silicon layer can be weakly electronically coupled into the crystalline silicon base. Such carrier injection has pre…
View article: Silicon-Rich Silicon Carbide Hole-Selective Rear Contacts for Crystalline-Silicon-Based Solar Cells
Silicon-Rich Silicon Carbide Hole-Selective Rear Contacts for Crystalline-Silicon-Based Solar Cells Open
The use of passivating contacts compatible with typical homojunction thermal processes is one of the most promising approaches to realizing high-efficiency silicon solar cells. In this work, we investigate an alternative rear-passivating c…
View article: Zinc tin oxide as high-temperature stable recombination layer for mesoscopic perovskite/silicon monolithic tandem solar cells
Zinc tin oxide as high-temperature stable recombination layer for mesoscopic perovskite/silicon monolithic tandem solar cells Open
Perovskite/crystalline silicon tandem solar cells have the potential to reach efficiencies beyond those of silicon single-junction record devices. However, the high-temperature process of 500 °C needed for state-of-the-art mesoscopic perov…
View article: Monolithic Si nanocrystal/crystalline Si tandem cells involving Si nanocrystals in SiC
Monolithic Si nanocrystal/crystalline Si tandem cells involving Si nanocrystals in SiC Open
Monolithic tandem cells involving a top cell with Si nanocrystals embedded in SiC (Si NC/SiC) and a c‐Si bottom cell have been prepared. Scanning electron microscopy shows that the intended cell architecture is achieved and that it survive…
View article: Sputtered rear electrode with broadband transparency for perovskite solar cells
Sputtered rear electrode with broadband transparency for perovskite solar cells Open
Due to their high efficiencies combined with simple and cost-effective device fabrication, perovskite solar cells are promising candidates as top cells in tandem devices. For this application, the perovskite solar cell must be highly trans…
View article: High-efficiency silicon heterojunction solar cells: Status and perspectives
High-efficiency silicon heterojunction solar cells: Status and perspectives Open
Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-…
View article: Structural parameters effect on the electrical and electroluminescence properties of silicon nanocrystals/SiO<sub>2</sub> superlattices
Structural parameters effect on the electrical and electroluminescence properties of silicon nanocrystals/SiO<sub>2</sub> superlattices Open
The effect of the oxide barrier thickness (tSiO2) reduction and the Si excess ([Si]exc) increase on the electrical and electroluminescence (EL) properties of Si-rich oxynitride (SRON)/SiO2 superlattices (SLs) is investigated. The active la…