Interdigitated-back-contacted silicon heterojunction solar cells featuring novel MoO_x-based contact stacks

The fabrication process of interdigitated-back-contacted silicon heterojunction (IBC-SHJ) solar cells has been significantly simplified with the development of the so-called tunnel-IBC architecture. This architecture utilizes a highly conductive (p)-type nanocrystalline silicon (nc-Si:H) layer deposited over the full substrate area comprising...

Optical Simulation-Aided Design and Engineering of Monolithic Perovskite/Silicon Tandem Solar Cells

Monolithic perovskite/c-Si tandem solar cells have attracted enormous research attention and have achieved efficiencies above 30%. This work describes the development of monolithic tandem solar cells based on silicon heterojunction (SHJ) bottom- and perovskite top-cells and highlights light management techniques assisted by optical simulation...

Impact of the Current on Reverse Bias Degradation of Perovskite Solar Cells

Nonequal current generation in the cells of a photovoltaic module, e.g., due to partial shading, leads to operation in reverse bias. This quickly causes a significant efficiency loss in perovskite solar cells. We report a more quantitative investigation of the reverse bias degradation. Various small reverse biases (negative voltages) were...

Slow Shallow Energy States as the Origin of Hysteresis in Perovskite Solar Cells

Organic-inorganic metal halide perovskites have attracted a considerable interest in the photovoltaic scientific community demonstrating a rapid and unprecedented increase in conversion efficiency in the last decade. Besides the stunning progress in performance, the understanding of the physical mechanisms and limitations that govern perovskite...

Controllable Simultaneous Bifacial Cu-Plating for High-Efficiency Crystalline Silicon Solar Cells

Bifacial (BF) copper-plated crystalline silicon solar cell is an attractive topic to concurrently reduce silver consumption and maintain good device performance. However, it is still challenging to realize a high aspect ratio (AR) of the metal fingers. Herein, a new type of hybrid-shaped Cu finger is electromagnetically fabricated in a BF...

Efficient Continuous Light-Driven Electrochemical Water Splitting Enabled by Monolithic Perovskite-Silicon Tandem Photovoltaics

Solar-assisted water electrolysis is a promising technology for storing the energy of incident solar irradiation into hydrogen as a fuel. Here, an integrated continuous flow electrochemical reactor coupled to a monolithic perovskite-silicon tandem solar cell is demonstrated that provides light-driven electrochemical solar-to-hydrogen...

Effects of (i)a-Si: H deposition temperature on high-efficiency silicon heterojunction solar cells

Excellent surface passivation induced by (i)a-Si:H is critical to achieve high-efficiency silicon heterojunction (SHJ) solar cells. This is key for conventional single-junction cell applications but also for bottom cell application in tandem devices. In this study, we investigated the effects of (i)a-Si:H deposition temperature on passivation...

Achieving 23.83% conversion efficiency in silicon heterojunction solar cell with ultra-thin MoO_x hole collector layer via tailoring (i)a-Si:H/MoO_x interface

Thin films of transition metal oxides such as molybdenum oxide (MoO_x) are attractive for application in silicon heterojunction solar cells for their potential to yield large short-circuit current density. However, full control of electrical properties of thin MoO_x layers must be mastered to obtain an efficient hole...

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...

The role of heterointerfaces and subgap energy states on transport mechanisms in silicon heterojunction solar cells

The contact resistivity is a key parameter to reach high conversion efficiency in solar cells, especially in architectures based on the so-called carrier-selective contacts. The importance of contact resistivity relies on the evaluation of the quality of charge collection from the absorber bulk through adjacent electrodes. The electrode...

Implantation-based passivating contacts for crystalline silicon front/rear contacted solar cells

In this work, we develop SiO_x/poly-Si carrier-selective contacts grown by low-pressure chemical vapor deposition and boron or phosphorus doped by ion implantation. We investigate their passivation properties on symmetric structures while varying the thickness of poly-Si in a wide range (20-250 nm). Dose and energy of implantation...

Strategy to mitigate the dipole interfacial states in (i)a-Si:H/MoOxpassivating contacts solar cells

Electrical simulations show that the dipole formed at (i)a-Si:H/MoOx interface can explain electrical performance degradation. We experimentally manipulate this interface by a plasma treatment (PT) to mitigate the dipole strength without harming the optical response. The optimal PT + MoOx stack results in strongly improved electrical...

Versatility of nanocrystalline silicon films: From thin-film to perovskite/c-Si tandem solar cell applications

Doped hydrogenated nanocrystalline (nc-Si:H) and silicon oxide (nc-SiO^x:H) materials grown by plasma-enhanced chemical vapor deposition have favourable optoelectronic properties originated from their two-phase structure. This unique combination of qualities, initially, led to the development of thin-film Si solar cells allowing the...

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...

Front and rear contact Si solar cells combining high and low thermal budget Si passivating contacts

In this work we develop a rear emitter silicon solar cell integrating carrier-selective passivating contacts (CSPCs) with different thermal budget in the same device. The solar cell consists of a B-doped poly-Si/SiO_x hole collector and an i/n hydrogenated amorphous silicon (a-Si:H) stack acting as electron collector placed on the...