GaAs based photovolatic cells

Photovoltaic cell of GaAs to convert monochromatic radiation with a wavelength of 800-850 nm.

Power-by-Light

R&D Services

Our R&D services comprise:

Epitaxy Development

Due to excellent material quality, our laser power converters achieve the highest efficiencies. The semiconductor material is optimally matched to the laser wavelength, and therefore thermalization losses are reduced to a minimum.

Photovoltaic Cell Development

We optimize cell designs for the various application needs and laser wavelengths. With advanced cell architectures we realize monolithic series-connected devices with higher output voltages.

Characterization of Laser Power Converters

At our laser-based measurement station, we investigate laser power converters under monochromatic light. We also measure the spectral response and quantum efficiency. Our spectrally and spatially resolved electroluminescence measurements provide us with information about the material properties and quality.

Automated Packaging

To assemble the laser power converters, we use our in-house industry-level packaging equipment. This equipment is also used for pilot and small series production.

System Integration

To reach our goal of an all-inclusive system integration, we consider the optical coupling, the thermal connection between the cell and package and the integration of the downstream electronics. Additionally we work on combining power and data transmission.

Reliability Investigations

Using degradation studies and accelerated aging tests, we investigate the reliability of components and assemblies, focusing on packaging.

 

 

Optical power transmission with Power-by-Light systems (also known as Power-over-Fiber) is an elegant method for powering sensors or actuators, when a conventional power supply with copper cables is limited or not available. The reasons for this are manifold, for example: the need for galvanic isolation, high voltage or lightning protection, electromagnetic interference, wireless transmission, weight reduction, spark protection, corrosion resistance, high magnet fields or rotating systems. There are a wide variety of applications for Power-by-Light systems such as structural health monitoring of wind turbines, fuel gauges in airplanes, monitoring of high voltage lines, optical power supply of automotive sensors, biosensors in smart implants, or the monitoring of passive optical networks.

At Fraunhofer ISE we develop special photovoltaic cells for Power-by-Light applications. These so-called laser power converters convert monochromatic light into electricity with highest efficiency. Currently our research focuses on developing materials for specific laser wavelengths, optimizing the cell structure for converting monochromatic light and developing advanced cell concepts for increasing the output voltage. Our other research topics consist of characterizing cells under monochromatic light, reliability investigations, as well as packaging and system integration. The latter also includes the combination of power and data transmission and coupling the systems to the electronics or electronic circuitry.

For a laser power converter based on GaAs, which was prepared by thin-film technology with a back-surface mirror, we achieved an opto-electric conversion efficiency of 67.3%, measured with a laser wavelength of 860 nm at an irradiance of 9.6 W/cm².

 

 

On this topic from our research blog »Innovation4E«:

Photovoltaic Cells for Laser Light: Optical Power Transmission for Sensor Electronics

Blog post by Henning Helmers

Dr. Henning HelmersWhen one thinks of photovoltaic cells, then it is usually in connection with the conversion of solar radiation into electricity, a main research area at Fraunhofer ISE in line with the energy transformation. However, researchers at Fraunhofer ISE are also working on another application for photovoltaic (PV) cells: Power-by-Light systems (also known as Power-over-Fiber) in which optical power transfer is used to supply electricity to electronics. Energy transmission is carried out in the form of light, and the photovoltaic cell is not used as a “solar cell,” but rather to convert the transmitted laser light into electricity.

Read more on blog.innovation4e.de

Selected Research Projects

 

ASHLEY

Avionics Systems Hosted on a Distributed Modular Electronics Large Scale Demonstrator for Multiple Type of Aircraft

 

OPTOWIND

Optically Powered Sensor Networks for Wind Energy

 

LightBridge

Electronic System for the Wireless Power Supply of a Subretinal Micro Implant

 

Current publications - Power-by-Light: