Monolithic 24  cm² flexible triple-junction solar cell encapsulated module based on the ipsilateral electrode welding...

Area of Science:

• Materials Science
• Renewable Energy Engineering
• Photovoltaics

Background:

• Inverted metamorphic multi-junction solar cells offer flexibility and light weight, making them ideal for stratospheric flight.
• Current fabrication methods for these cells can be complex and may risk damaging the delicate structures.

Purpose of the Study:

• To simplify the fabrication process of GaInP/GaAs/InGaAs solar cells.
• To develop a reliable encapsulation method for large-sized flexible solar cells.
• To evaluate a novel ipsilateral welding technology using Ti/Au electrodes.

Main Methods:

• Ipsilateral welding technology utilizing Ti/Au electrodes.
• Annealing process at 200°C for 2 hours to optimize electrode properties.
• Fabrication and testing of individual solar cells and flexible solar cell modules.

Main Results:

• Achieved a low specific contact resistivity of 2.9×10^-7 Ω⋅cm² for the Ti/Au electrode after annealing.
• Demonstrated stable ohmic contact performance after thermal cycling tests.
• A 24 cm² solar cell reached a conversion efficiency of 34.74%.
• A flexible solar cell module achieved an efficiency of 32.82% under AM 1.5G illumination.

Conclusions:

• The proposed ipsilateral welding technology based on Ti/Au electrodes simplifies fabrication and encapsulation of flexible multi-junction solar cells.
• The Ti/Au electrode offers excellent electrical properties and thermal stability, crucial for reliable solar cell performance.
• This technology enables the development of high-efficiency flexible solar cells for demanding applications like stratospheric flight.