New Energy
Okada Laboratory

Innovative R&D on next-generation high-efficiency solar cells and low-cost production technologies

High-efficiency beyond the present silicon solar cell technology

New semiconductor materials and new quantum nanostructures are exploited in order to achieve high-efficiency photovoltaic solar energy conversion reaching 50% under concentrated sunlight and innovation on alternative energy technologies.
Research target includes:

• (1) Intermediate band solar cells with photocurrent enhancement by two-step infrared photon absorption using quantum dot arrays or highly mismatched semiconductor alloys.
• (2) Multi-junction solar cells with improved spectral matching for sunlight by stacked semiconductor junctions.
• (3) Hot carrier solar cells with high output voltage by hot carrier extraction.

Light-weight and Low-cost thin-film solar cells

Epitaxial lift-off (ELO) technique is developed in order to peel-off III-V compound semiconductor thin-film solar cell from the substrate. This allows to reuse the expensive substrate for many times, which can lead to a drastic reduction of the production cost. Thin-film solar cells are light-weight and flexible and a wide commercial application (such as solar-powered EVs) becomes possible, which will contribute to future low-carbon and sustainable society.

Hybrid concentrator photovoltaic/thermal module

Hybrid concentrator photovoltaic and thermal module, so-called CPV-T, is developed. High efficiency energy usage can be realized by co-generation of electricity via photovoltaics and thermal energy through collection via hot water.

Member

• 
• • Professor
    Yoshitaka OKADA
  Specialized field: Next-generation solar cells, Semiconductor crystal growth, Epitaxial lift-off thin-film solar cells

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