A5069832350- Silicon and Solar Cell Technologies
- Semiconductor materials and interfaces
- Integrated Circuits and Semiconductor Failure Analysis
- Thin-Film Transistor Technologies
- Semiconductor materials and devices
- Silicon Nanostructures and Photoluminescence
- Advancements in Semiconductor Devices and Circuit Design
- solar cell performance optimization
- Ion-surface interactions and analysis
- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- Photovoltaic System Optimization Techniques
- Advanced Materials Characterization Techniques
- Silicon Carbide Semiconductor Technologies
- Diamond and Carbon-based Materials Research
Fraunhofer Institute for Solar Energy Systems
2018-2025
Australian National University
2022
Leibniz University Hannover
2022
University of Freiburg
2018-2021
Abstract Passivating contacts based on poly‐Si/SiO x structures also known as TOPCon (tunnel oxide passivated contacts) have a great potential to improve the efficiency of crystalline silicon solar cells, resulting in more than 26% and 24% for laboratory industrial respectively. This publication gives an overview historical development such contact which started already 1980s describes current state‐of‐the‐art industry. In order demonstrate variety scientific technological research, four...
Passivating contacts based on a thin SiO x layer and doped Si (TOPCon) are an appealing choice for pushing the efficiency of solar cells. One way to deposit is utilize radio‐frequency direct plasma‐enhanced chemical vapor deposition as commonly used in industry silicon nitride. However, due low operating frequency kHz range, there concerns that ion bombardment might damage thus prevent suitable surface passivation. We demonstrate this not case. Instead, application these layers c‐Si results...
Recently, the charge carrier transport mechanism of passivating contacts, which feature an ultra-thin oxide layer, has been investigated by studying temperature-dependent current-voltage (I-V) characteristics. The measurement revealed that tunneling is dominant path for tunnel passivated contact (TOPCon) with wet chemically grown layer. Furthermore, higher annealing temperatures led to deterioration surface passivation most likely because excessive pinhole formation. In this contribution, we...
A central quantity to assess the high quality of monocrystalline silicon (on scales beyond mere purity) is minority charge carrier lifetime. We demonstrate that lifetime in purity float zone material can be improved existing observations, thanks a deeper understanding grown-in defects and how they permanently annihilated. In first step we investigate influence several process sequences on by applying low temperature superacid passivation treatment. find pre-treatment consisting an oxidation...
ABSTRACT In this work, we demonstrate the formation of local boron‐doped, SiOₓ/p + poly‐Si structures using wet chemical etching by direct printing boron‐ink. FlexTrail uses a very hollow (orders μm for diameter) glass capillary tube filled with boron ink onto silicon substrate. This process represents mask‐free approach TOPCon structures, enabling high‐efficiency tunnel oxide passivating contact (TOPCon) solar cells. The factors influencing etch‐back selectivity between intrinsic and...
This paper discusses how differently grown ultra-thin interfacial oxide of poly-Si based passivating contacts correspond to high-temperature annealing as well its sensitivity hydrogenation. It will be shown on symmetrical lifetime samples that tunnel (TOPCon) featuring thermally layer allow a higher optimum temperature than those with thin wet-chemically oxides. These TOPCon structures can yield an excellent passivation quality up 741 mV iVoc and 88% iFF. Moreover, annealed at low...
Front side recombination in tunnel oxide passivated contact solar cells is frequently described by the parameters j 0e for and 0e,met metallized front region. The combination of Al‐free metallization pastes current‐assisted formation has shown significant reduction . Such new approaches enable shallower doping profiles higher sheet resistances R , which turn also reduce In this study, we provide insight into how to overall recombination, tailoring boron dopant profile from atmospheric...
Epitaxially grown silicon wafers (EpiWafers) have a lower carbon footprint than conventional produced by ingot crystallization but also initial material quality which can be significantly improved gettering. We show that in situ gettering during the application of asymmetric n‐type and p‐type tunnel oxide passivating contacts (TOPCon) increases EpiWafers when fabricating bottom solar cells for perovskite‐silicon tandem device. In specific, effect TOPCon layers is compared to phosphorus...
The presented investigation focuses on different thermal activation processes and their influence the formation of a polysilicon tunnel junction as recombination layer in perovskite/silicon tandem solar cells. goals this are optimization comparison processing pathways to enable lean process integration. Various routes with annealing sequences for were examined, using laser‐based rapid (RTP) conventional furnace anneal. main challenge is control interdiffusion p‐ well n‐type dopants at...
Abstract Polycrystalline‐silicon/oxide (poly‐Si/SiO x ) passivating contacts for high efficiency solar cells exhibit excellent surface passivation, carrier selectivity, and impurity gettering effects. However, the ultrathin SiO interlayer can act as a diffusion barrier metal impurities this potentially slows down overall rate of poly‐Si/SiO structures. Herein, factors that determine blocking effects interlayers are identified investigated by examining two general types interlayers: 1.3 nm...
This paper discusses the successful realization of tunnel oxide passivated contacts (TOPCon) using industry-relevant PECVD equipment. It will be shown that batch-type direct plasma allows for a damage-free deposition doped a-Si onto an ultra-thin layer. Using symmetric test structures impact thermally or wet-chemically grown interfacial SiOx layer, as well influence poly-Si doping level on surface passivation quality discussed in detail. Maximum values 736 mV iVoc and 87.4 % iFF were...
Passivating contacts consisting of heavily doped polycrystalline silicon (poly-Si) and ultrathin interfacial oxide (SiOx) films enable the fabrication high-efficiency Si solar cells. The electrical properties working mechanism such poly-Si passivating depend on distribution dopants at their interface with underlying substrate Therefore, this distribution, particularly in vicinity pinholes SiOx film, is investigated work. Technology computer-aided design (TCAD) simulations were performed to...
In this work, we demonstrate the formation of local boron doped, p+ SiO x/ poly-Si structures using wet chemical etching by direct printing boron-ink FlexTrail printing. This process is a mask free approach for TOPCon high efficiency tunnel oxide passivated contact (TOPCon) solar cells. Factors affecting etch back selectivity between intrinsic and doped are studied. It found that pre-treatment diluted HF (1 wt%) before removal KOH solution most crucial to ensure selectivity. Etching native...
In this publication, the deposition of a‐Si(n) layers using an industrially relevant inline plasma‐enhanced chemical vapor (PECVD) tool for successful realization passivating contacts is reported. Dynamic has potential to increase production throughput and yield compared conventional cluster‐like PECVD tools which current standard a‐Si:H layers. Besides structural investigations concerning absorbance band gap energy these layers, dependence layer thickness PH 3 gas phase doping on implied...
Passivated contact cell architectures have the potential for higher efficiencies than currently dominant PERC technology. Further development requires greater understanding of passivation mechanism and surface related degradation, especially at polysilicon-oxide-crystalline silicon contacts. In particular, hydrogenation provided by high temperature firing dielectrics has been shown to govern both initial subsequent degradation this interface. Given nanoscale dimensions tunnelling oxide,...
Plasma-Enhanced Chemical Vapor Deposition (PECVD) is an attractive tool for TOPCon production, as it enables uniformly in situ doped amorphous silicon (a-Si) and dielectric layer depositions with high throughput. However, a lean process requires interfacial oxide growth the same tool. In this work, we use Plasma-Assisted N2O Oxidation (PANO) industrial kHz direct plasma reactor (centrotherm c.PLASMA) to grow deposit phosphorus a-Si(n) well SiNx on asymmetric lifetime samples. Before...