Explanipedia

Quasi-open circuit response times of single- and multi-junction InGaAs photonic power converters Open

Osbel Almora, D P Wilson, Carmine Pellegrino, David Lackner, Henning Helmers , et al. · 2025

Photonic power converters provide an emerging alternative to traditional metallic cabling due to their immunity to electromagnetic interference and for minimizing fire hazards as well as their ability to wirelessly power loads. In this wor…

Machine learning enhanced design and knowledge discovery for multi-junction photonic power converters Open

R. F. Hunter, Gavin P. Forcade, Yuri Grinberg, D. Paige Wilson, Meghan N. Beattie , et al. · 2025

Machine learning is proving to be a revolutionary tool across many disciplines, including optoelectronic device design. In this report, we compare classical and machine learning enhanced design optimization methodologies. We investigate, a…

Overcoming Material Incompatibility via 2D Free‐Surface Engineering Open

Youcef A. Bioud, Meriem Bouchilaoun, Waldemar Schreiber, Redouane Amrar, G. Patriarche , et al. · 2025

Heteroepitaxy has been pivotal in advancing both optoelectronics and microelectronics, driving the development of faster, more efficient devices across diverse applications. However, achieving high material quality remains challenging due …

Optimization of GaInP absorber design for indoor photovoltaic conversion efficiency above 40% Open

Malte Klitzke, Patrick Schygulla, Christoph Klein, Peter Kleinschmidt, Thomas Hannappel , et al. · 2025

Indoor photovoltaics (IPV) is a key technology for powering low-energy electronics, particularly Internet of Things devices, where wired power or frequent battery replacements are impractical. IPV cells convert artificial indoor light into…

Multi-junction laser power converters exceeding 50% efficiency in the short wavelength infrared Open

Gavin P. Forcade, D. Paige Wilson, Meghan N. Beattie, Carmine Pellegrino, Henning Helmers , et al. · 2025

Photonic or laser power converters are crucial components in power-by-light systems. However, their use in long-distance applications has been hindered by low efficiencies and output voltages within the optical fiber transmission window of…

Metalorganic Vapor‐Phase Epitaxy Growth of GaAs Rear‐Heterojunction Solar Cells at 94 µm/h Open

Christoph Klein, R. Lang, Jens Ohlmann, Frank Dimroth, David Lackner · 2025

In this study, a GaAs single‐junction solar cell with an absorber layer grown at a very high rate of 94 µm/h via metalorganic vapor‐phase epitaxy (MOVPE) is demonstrated, employing a low V/III ratio of 5. This approach enables the depositi…

Subcell‐Resolved EQE Method Using Reverse Voltage Biasing for Multijunction Photovoltaics With Overlapping Subcell Absorptance Open

Meghan N. Beattie, Michael Schachtner, Gerald Siefer, David Lackner, Oliver Höhn , et al. · 2025

External quantum efficiency (EQE) measurements of individual subcells in multijunction photovoltaic devices are essential to evaluate current matching and to iterate the design process. The standard light biasing technique used to measure …

Rear-heterojunction GaInP laser power converter with 59% monochromatic efficiency at 590 nm Open

Malte Klitzke, Oliver Höhn, Gerald Siefer, Henning Helmers, Frank Dimroth , et al. · 2025

Photonic power converters (PPCs) are devices that convert narrowband light at specific wavelengths into electrical energy based on the photovoltaic effect. They are used in optical power transmission systems, which offer advantages over co…

InP-on-GaAs engineered substrates: A pathway toward low-cost, high-efficiency optoelectronic device fabrication Open

Carmine Pellegrino, Frank Dimroth, Jens Ohlmann, Henning Helmers, David Lackner · 2025

Indium Phosphide (InP) plays a pivotal role in the semiconductor industry, particularly in the development of high-power, high-frequency optoelectronic devices that are essential for next-generation applications not only in telecommunicati…

GaAs//CuInGaSe‐Based Multijunction Solar Cells with 30% Efficiency Under Low Concentrated Sunlight Open

Kikuo Makita, Yukiko Kamikawa, Hidenori Mizuno, Ryuji Oshima, Yasushi Shoji , et al. · 2024

Multijunction (MJ) solar cells have demonstrated very high efficiencies (>30%) owing to the effective use of solar energy. Among these, the GaAs//CuInGaSe(CIGSe)‐based MJ solar cell is unique owing to its features, such as being lightweigh…

Sheet Resistance Optimization in (Al)GaInP Solar Cells for Concentrator Quadruple–Junction Solar Cells Open

Malte Klitzke, Patrick Schygulla, Jonas Schön, Oliver Höhn, Gerald Siefer , et al. · 2024

The reduction of the series resistance in multi‐junction solar cells is of high importance for attaining peak efficiencies in concentrator photovoltaics. This study showcases strategies to reduce the sheet resistance of the uppermost subce…

Table of Contents Open

Yang Zhao, Zhe Wan, Jun Guo, Y.-C Yang, Haozu Cheng , et al. · 2024

Monolithically integrated 940 nm VCSELs on bulk Ge substrates Open

Zeyu Wan, Yun-Cheng Yang, Wei‐Hsin Chen, Chih-Chuan Chiu, Yunlong Zhao , et al. · 2024

This research successfully developed an independent Ge-based VCSEL epitaxy and fabrication technology route, which set the stage for integrating AlGaAs-based semiconductor devices on bulk Ge substrates. This is the second successful Ge-bas…

Wafer‐bonded two‐terminal III‐V//Si triple‐junction solar cell with power conversion efficiency of 36.1% at AM1.5g Open

Patrick Schygulla, Ralph Müller, Oliver Höhn, Michael Schachtner, David Chojniak , et al. · 2024

In this work, we present the fabrication and analysis of a wafer‐bonded GaInP/GaInAsP//Si triple‐junction solar cell with 36.1% conversion efficiency under AM1.5g spectral illumination. The new cell design presents an improvement over prev…

Off-Axis Electron Holography of In-Situ-Biased Highly-Doped p-AlGaAs/n-GaInP Junctions for Solar Cell Applications Open

Vita Mergner, Malte Klitzke, Patrick Schygulla, David Lackner, András Kovács , et al. · 2024

Monolithically Integrated 940 nm Half VCSELs on Bulk Ge Substrates Open

Yunlong Zhao, Zeyu Wan, Jia Guo, Yun-Cheng Yang, Hao-Tien Cheng , et al. · 2023

High-quality n-type AlGaAs distributed Bragg reflectors (DBRs) and lnGaAs multiple quantum wells (MQWs) were successfully monolithically grown on 4-inch off-cut Ge (100) wafers. Even without any design and process optimization for the Ge s…

Proton radiation hardness of GaInAsP alloys for space solar cell applications Open

Carmine Pellegrino, Jonas Schön, R. Lang, Frank Dimroth, Claus G. Zimmermann , et al. · 2023

Recent technology development in space mission design has raised a demand for space solar cells with a higher level of radiation tolerance as compared with state‐of‐the‐art, commercially available products. Therefore, new material systems …

Study of monolithically integrated 940 nm AlGaAs distributed Bragg reflectors on graded GaAsP/bulk Si substrates Open

Jia Guo, Yunlong Zhao, Markus Feifel, Hao-Tien Cheng, Yun-Cheng Yang , et al. · 2023

We report the fabrication of monolithically integrated 940 nm AlGaAs distributed Bragg reflectors (DBRs) on graded GaAsP/Si substrates. Low-density surface bumps and cross-hatch patterns were observed on the DBR surfaces. Cross-sectional D…

Significance of cardiovascular comorbidity in patients with chronic myelomonocytic leukemia Open

David Lackner, Klaus Geißler · 2022

Monolithically integrated 940 nm half VCSELs on bulk Ge substrates Open

Yunlong Zhao, Jia Guo, Markus Feifel, Hao-Tien Cheng, Yun-Cheng Yang , et al. · 2022

High quality n-type AlGaAs distributed Bragg reflectors (DBRs) and lnGaAs multiple quantum wells were successfully monolithically grown on 4-inch off-cut Ge (100) wafers. The grown structures have photoluminescence spectra and reflectance …

Study of monolithically integrated 940 nm AlGaAs distributed Bragg reflectors on graded GaAsP/bulk Si substrates Open

Jia Guo, Yunlong Zhao, Markus Feifel, Hao-tien Cheng, Yun-cheng Yang , et al. · 2022

We report the fabrication of monolithically integrated 940 nm AlGaAs distributed Bragg reflectors (DBRs) on graded GaAsP/Si substrates. Low-density surface bumps and cross-hatch patterns were observed on the DBR surfaces. Cross-sectional D…

Improvements in ultra‐light and flexible epitaxial lift‐off GaInP/GaAs/GaInAs solar cells for space applications Open

Jonas Schön, G.M.M.W. Bissels, P. Mulder, Rosalinda H. van Leest, Natasha Gruginskie , et al. · 2022

A thin, lightweight, flexible solar cell is developed that maximizes the power‐to‐mass ratio under AM0 illumination and has a competitive efficiency after typical high energy electron irradiation. The inverted metamorphic triple junction (…

Monolithic integration of 940 nm AlGaAs distributed Bragg reflectors on bulk Ge substrates Open

Yunlong Zhao, Jia Guo, Markus Feifel, Hao-Tien Cheng, Yun-Cheng Yang , et al. · 2022

High quality 940 nm Al x Ga 1-x As n-type distributed Bragg reflectors (DBRs) were successfully monolithically grown on off-cut Ge (100) substrates. The Ge-DBRs have reflectivity spectra comparable to those grown on conventional bulk GaAs …

Increasing transferability between design and epitaxial growth of multi-junction solar cells Open

Patrick Schygulla, Malte Klitzke, Oliver Höhn, Felix Predan, David Lackner , et al. · 2022

In this work we report on a procedure to increase the reproducibility of multi-junction solar cell growth. This is achieved by applying a systematic offset to room-temperature photoluminescence measurement to match the required band gap fo…

Ultra-lightweight and flexible inverted metamorphic four junction solar cells for space applications Open

Malte Klitzke, Jonas Schön, Rosalinda H. van Leest, G.M.M.W. Bissels, Elias Vlieg , et al. · 2022

In this work an inverted metamorphic four junction (IMM4J) solar cell with 30.9% conversion efficiency in beginning of life conditions under the AM0 (1367 W/m 2 ) spectrum is presented. Additionally, our newest improved IMM3J cell, consist…

Monolithic integration of 940 nm AlGaAs distributed Bragg reflectors on bulk Ge substrates Open

Yunlong Zhao, Jia Guo, Markus Feifel, Hao-tien Cheng, Yun-cheng Yang , et al. · 2021

High quality 940 nm Al$_x$Ga$_{1-x}$As n-type distributed Bragg reflectors (DBRs) were successfully monolithically grown on off-cut Ge (100) substrates. The Ge-DBRs have reflectivity spectra comparable to those grown on conventional bulk G…

Two‐terminal III–V//Si triple‐junction solar cell with power conversion efficiency of 35.9 % at AM1.5g Open

Patrick Schygulla, Ralph Müller, David Lackner, Oliver Höhn, Hubert Hauser , et al. · 2021

III–V//Si multijunction solar cells offer a pathway to increase the power conversion efficiency beyond the fundamental Auger limit of silicon single‐junctions. In this work, we demonstrate how the efficiency of a two‐terminal wafer‐bonded …

Counterbalancing light absorption and ionic transport losses in the electrolyte for integrated solar water splitting with III–V/Si dual-junctions Open

Moritz Kölbach, Ciler Özen, Oliver Höhn, David Lackner, Markus Feifel , et al. · 2021

Recently, significant progress in the development of III–V/Si dual-junction solar cells has been achieved. This not only boosts the efficiency of Si-based photovoltaic solar cells but also offers the possibility of highly efficient green h…

Middle Cell Development for Wafer-Bonded III-V//Si Tandem Solar Cells Open

Patrick Schygulla, Friedemann D. Heinz, Frank Dimroth, David Lackner · 2021

This article focuses on the material properties of two III-V semiconductors, AlGaAs and GaInAsP, and their usage as middle cell absorber materials in a wafer-bonded III-V//Si triple-junction solar cell. To this end single-junction solar ce…

Pushing the Boundaries of Photovoltaic Light to Electricity Conversion: A GaAs Based Photonic Power Converter with 68.9% Efficiency Open

Henning Helmers, Esther López, Oliver Höhn, David Lackner, Jonas Schön , et al. · 2021

We present recent results achieved in the field of photonic power conversion, i.e. monochromatic light to electricity conversion, using photovoltaic cells. Based on a thin film processing approach we leverage photon recycling and optical r…

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