Combined Fabrication and Performance Evaluation of TOPCon Back-Contact Solar Cells with Lateral Power Metal-Oxide-Semiconductor Field-Effect Transistors on a Single Substrate

Nowadays, an increasing share of photovoltaic (PV) systems makes use of module- or submodule-level power electronics (PE). Furthermore, PE is used in stand-alone devices powered by PV-storage solutions. One way to facilitate further implementation of PE in PV applications is to integrate PE components into crystalline silicon PV cells. Herein...

In Situ Annealing of Boron-Doped Amorphous Silicon Layers Using APCVD Technology

In this work, we developed an in situ annealing process to crystallize boron-doped amorphous silicon [a-Si(p+)] layers deposited by atmospheric pressure chemical vapour deposition (APCVD) to form boron-doped polycrystalline silicon [poly-Si(p+)] layers. The influence of the temperature profiles during a-Si(p+) inline deposition on structural,...

Poly-SiO_x Passivating Contacts with Plasma-Assisted N₂O Oxidation of Silicon (PANO-SiO_x)

Passivating contacts are crucial for realizing high-performance crystalline silicon solar cells. Herein, contact formation by plasma-enhanced chemical vapor deposition (PECVD) followed by an annealing step is focused on. Poly-SiO_x passivating contacts by combining plasma-assisted N₂O-based oxidation of silicon (PANO-SiO...

Towards bifacial silicon heterojunction solar cells with reduced TCO use

Reducing indium consumption, which is related to the transparent conductive oxide (TCO) use, is a key challenge for scaling up silicon heterojunction (SHJ) solar cell technology to terawatt level. In this work, we developed bifacial SHJ solar cells with reduced TCO thickness. We present three types of In₂O₃-based TCOs,...

Room-temperature sputtered tungsten-doped indium oxide for improved current in silicon heterojunction solar cells

The window layers limit the performance of silicon heterojunction (SHJ) solar cells with front and back contacts. Here, we optimized tungsten-doped indium oxide (IWO) film deposited by radio frequency magnetron sputtering at room temperature. The opto-electrical properties of the IWO were manipulated when deposited on top of thin-film silicon...

Design and optimization of hole collectors based on nc-SiO_x:H for high-efficiency silicon heterojunction solar cells

Low activation energy (E_a) and wide bandgap (E_g) are essential for (p)-contacts to achieve effective hole collection in silicon heterojunction (SHJ) solar cells. In this work, we study Plasma-Enhanced Chemical Vapor Deposition p-type hydrogenated nanocrystalline silicon oxide, (p)nc-SiO_x:H, combined with (p)nc...

Ultra-thin electron collectors based on nc-Si:H for high-efficiency silicon heterojunction solar cells

Low parasitic absorption and high conductivity enable (n)-type hydrogenated nanocrystalline silicon [(n)nc-Si:H], eventually alloyed with oxygen [(n)nc-SiO_x:H], to be deployed as window layer in high-efficiency silicon heterojunction (SHJ) solar cells. Besides the appropriate opto-electrical properties of these nanocrystalline...

Characterization of the defect density states in MoO_x for c-Si solar cell applications

Thin layers of MoO_x have been deposited by thermal evaporation followed by post-deposition annealing. The density of states distributions of the MoO_x films were extracted deconvoluting the absorption spectra, measured by a photothermal deflection spectroscopy setup, including the small polaron contribution. Results...

Solar cells based on n⁺-AZO/p-BaSi₂ heterojunction: Advanced opto-electrical modelling and experimental demonstration

We performed advanced opto-electrical simulations on thin-film BaSi₂ solar cells. First, absorption spectra of BaSi₂-pn homojunction solar cells on Si substrate were calculated based on flat and/or pyramidally-textured surfaces, wherein 20-nm-thick n⁺-BaSi₂ was the topmost electron transport layer....

Doped hydrogenated nanocrystalline silicon oxide layers for high-efficiency c-Si heterojunction solar cells

Hydrogenated nanocrystalline silicon oxide (nc-SiO_x:H) layers exhibit promising optoelectrical properties for carrier-selective-contacts in silicon heterojunction (SHJ) solar cells. However, achieving high conductivity while preserving crystalline silicon (c-Si) passivation quality is technologically challenging for growing thin...

Sub-gap defect density characterization of molybdenum oxide: An annealing study for solar cell applications

The application of molybdenum oxide in the photovoltaic field is gaining traction as this material can be deployed in doping-free heterojunction solar cells in the role of hole selective contact. For modeling-based optimization of such contact, knowledge of the molybdenum oxide defect density of states (DOS) is crucial. In this paper, we...

Transparent silicon carbide/tunnel SiO₂ passivation for c-Si solar cell front side: Enabling J_sc > 42 mA/cm² and iV_oc of 742 mV

N-type microcrystalline silicon carbide (μc-SiC:H(n)) is a wide bandgap material that is very promising for the use on the front side of crystalline silicon (c-Si) solar cells. It offers a high optical transparency and a suitable refractive index that reduces parasitic absorption and reflection losses, respectively. In this work, we...

Analysis of Transition Metal Oxides based Heterojunction Solar Cells with S-shaped J-V curves

The use of transition metal oxides for the selective carrier contact in the crystalline silicon solar cells technology is rising to interest for the excellent optoelectrical properties of these materials whose implementation, however, can result in lousy performing cells due to an S-shaped electrical characteristic. In this paper, we fabricated...

Realizing the Potential of RF-Sputtered Hydrogenated Fluorine-Doped Indium Oxide as an Electrode Material for Ultrathin SiO _x/Poly-Si Passivating Contacts

In high-efficiency silicon solar cells featuring carrier-selective passivating contacts based on ultrathin SiOx/poly-Si, the appropriate implementation of transparent conductive oxide (TCO) layers is of vital importance. Considerable deterioration in passivation quality occurs for thin poly-Si-based devices owing to the sputtering damage...

High-Mobility Hydrogenated Fluorine-Doped Indium Oxide Film for Passivating Contacts c-Si Solar Cells

Broadband transparent conductive oxide layers with high electron mobility (μ_e) are essential to further enhance crystalline silicon (c-Si) solar cell performances. Although metallic cation-doped In₂O₃ thin films with high μ_e (>60 cm² V^-1 s^-1) have been extensively...

High temperature oxidation pre-treatment of textured c-Si wafers passivated by a-Si:H

This work shows an alternative surface cleaning method for c-Si wafers to replace the standard chemical procedures as RCA or HNO ₃ which involve hazardous chemicals or unstable processes. The method consists in a high-temperature oxidation treatment (HTO) performed in a classical tube furnace that incorporates organic and metal...

Thin-film amorphous silicon germanium solar cells with p-and n-type hydrogenated silicon oxide layers

Mixed-phase hydrogenated silicon oxide (SiOx:H) is applied to thin-film hydrogenated amorphous silicon germanium (a-SiGe:H) solar cells serving as both p-doped and n-doped layers. The bandgap of p-SiOx:H is adjusted to achieve a highly-transparent window layer while also providing a strong electric field. Bandgap grading of n-SiOx:H is designed...

Poly-Si(O)x passivating contacts for high-efficiency c-Si IBC solar cells

Highest conversion efficiency in crystalline silicon (c-Si) solar cells can be enabled by quenching minority carriers' recombination at c-Si/contact interface owing to carrier-selective passivating contacts. With the semi-insulating poly-crystalline silicon (SIPOS, poly-Si) a very good passivation of c-Si surfaces was obtained. We have...