4-Junction GaAs Based Thin Film Photonic Power Converter with Back Surface Reflector for Medical Applications

2022

Photonics

The high-efficiency capabilities of multijunction laser power converters are demonstrated for high-power applications with an optical input of around 1470 nm. The InP-based photovoltaic power converting III-V semiconductor devices are designed here, with 10 lattice-matched subcells (PT10-InGaAs/InP), using thin InGaAs absorbing layers connected by transparent tunnel junctions. The results confirm that such long-wavelength power converter devices are capable of producing electrical output voltages greater than 4–5 V. The characteristics are compatible with common electronics requirements, and the optical input is well suited for propagation over long distances through fiber-based optical links. Conversion efficiencies of ~49% are measured at electrical outputs exceeding 7 W for an input wavelength of 1466 nm at 21 °C. The Power Converter Performance Chart has been updated with these PT10-InGaAs/InP results.

Section: Introductionmentioning

confidence: 99%

High-Efficiency and High-Power Multijunction InGaAs/InP Photovoltaic Laser Power Converters for 1470 nm

2022

Photonics

“…Our recent Power Converter Performance Chart [41,47] clearly highlights that multijunction OPCs are most advantageous to obtain high device performance. The research related to photovoltaic devices also suggests other potential future device improvements [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67], as well as new optical wireless power transmission (OWPT) applications and design strategies for future systems [68][69][70][71][72][73][74][75][76][77][78].…”

Section: Introductionmentioning

confidence: 99%

74.7% Efficient GaAs-Based Laser Power Converters at 808 nm at 150 K

2022

Photonics

High-efficiency multijunction laser power converters are demonstrated for low temperature applications with an optical input at 808 nm. The photovoltaic power converting III-V semiconductor devices are designed with GaAs absorbing layers, here with 5 thin subcells (PT5), connected by transparent tunnel junctions. Unprecedented conversion efficiencies of up to 74.7% are measured at temperatures around 150 K. At temperatures around 77 K, a remarkably low bandgap offset value of Woc = 71 mV is obtained at an optical input intensity of ~7 W/cm2. At 77 K, the PT5 retains an efficiency of 65% with up to 0.3 W of converted output power.

Perspective on photovoltaic optical power converters

Journal of Applied Physics

2021

Optical wireless power transmission (OWPT) can be used for applications that cannot access traditional power using metal wires. Photovoltaic power-converting III-V semiconductor devices are the core components required for achieving such remote and galvanically isolated power deployments. The development of high-efficiency power converters has already propelled several sensors and probe applications. This growing applied physics field is leveraging the use of ubiquitous laser diode products, now commonly available at various wavelengths. Novel multijunction designs, based on the vertical epitaxial heterostructure architecture devices, have recently allowed fiber-based and free-space applications to quickly progress to higher electrical powers and to benefit from other laser wavelengths. Here, we discuss the perspectives of such multijunction power converters from the viewpoint of realizing additional OWPT deployments and for enabling more probe, sensor, or electronic subsystem power capabilities. The Perspective hence provides a roadmap for devices achieving not only higher conversion efficiency, but also elaborates on the practical aspects necessary to concurrently push the power converters to higher output powers. The photovoltaic multijunction power-converting device is particularly a game-changer for smartly increasing the output voltage and therefore maintaining practical optimal external loads at high laser input powers. Examples of conversion efficiencies above 60% for output powers up to 17.5 W are demonstrated at ∼808 nm in this study, and up to 22 W of output power is obtained with an efficiency of 48.9% at ∼980 nm.