1064 nm InGaAsP multi-junction laser power converters via reverse-bias method

Area of Science:

• Optoelectronics
• Semiconductor Devices
• Wireless Power Transfer

Background:

• Laser power converters (LPCs) are crucial for efficient wireless energy transmission.
• Optimizing LPC design is essential for maximizing energy conversion efficiency.

Purpose of the Study:

• To design and fabricate high-efficiency single- and multi-junction 1064 nm laser power converters on InP substrates.
• To demonstrate a systematic design optimization approach for multi-junction LPCs.

Main Methods:

• Fabrication of single- and multi-junction LPCs on InP substrates.
• Optimization of tunnel junctions and subcell thicknesses.
• Reverse-bias analysis for current mismatch and absorption coefficient extraction.

Main Results:

• A double-junction LPC achieved 45.7% efficiency at 10°C and 11.504 W/cm².
• An initial six-junction LPC reached 39.8% efficiency at 7°C and 30.6 W/cm².
• Redesigned six-junction LPC achieved 42.4% efficiency at 5°C and 28 W/cm² after optimization.

Conclusions:

• The study successfully demonstrated a systematic design optimization for multi-junction LPCs.
• Optimized LPCs show significant potential for improving wireless energy transmission efficiency.
• Accurate material property extraction (e.g., InGaAsP absorption coefficient) is key to performance enhancement.