Dual-Wavelength Laser Power Converters Equipped With Intermediate Bands Compatible With Highly Efficient Solar Cells

This article propose the basic structure of laser power converters (LPCs) on the basis of intermediate-band solar cells (IB-SCs) assisted by the quantum ratchet (QR) mechanism. The LPCs convert efficiently both high-power and low-cost laser light of 800−1000 nm in wavelength and eye-safe laser light of ∼1500 nm to electricity. Furthermore, the LPCs operate as highly efficient SCs. Thus, the proposed dual-wavelength (DW) LPCs fulfill the functions required for LPCs used for optical wireless power transmission to driving electric vehicles; the solar-cell function charges the secondary batteries anywhere during daytime. I designed the electronic band structures of the DW-LPCs and calculated the limiting conversion efficiencies, revealing that the DW-LPCs equipped with the QRs potentially yield high conversion efficiencies for each light competitive with those of the conventional single-function devices dedicated. However, new IB materials must be developed to realize the high efficiency, because the required electronic band structures are significantly different from those of previously reported IB-SC materials.