Semiconductor/dielectric half-coaxial nanowire arrays for large-area nanostructured photovoltaics

We present a simple assembly strategy of single nanowires (NWs) to form half-coaxial nanowire arrays (NWAs) which can be easily realized in large size by standard pattering and deposition techniques. Through the finite-difference time-domain simulation, we show that the proposed half-coaxial NWAs effectively preserve the leaky modes resonances within single NWs and consequently achieve strong absorption enhancement under optimization of various structural factors. The best half-coaxial NWAs with 100 nm thick absorbing shell offer equivalent light absorption of more than 400 nm thick planar film. Benefiting from the >75% cut of the required thickness of the absorbing layer, the performances of the demonstrated half-coaxial NWAs based a-Si thin film solar cell also gain significant improvement.