Wide spectral response and ambient air-stable nanowire window-absorber type solar cells

Use of embedded CdS nanowires is demonstrated for partially overcoming the spectral transmission loss and the low mechanical and electrical robustness of planar CdS window layer and thus enhancing the quantum efficiency and reliability of CdS-CdTe solar cells. Power conversion efficiency of 12% is achieved, and aging and reliability are improved by approximately 3 times in un-encapsulated cells, over their traditional planar CdS counterparts. A nearly ideal spectral response of quantum efficiency at a wide spectrum range provides evidence for enhanced light absorption and carrier generation and collection in the absorber layer. Our results prove the efficacy of this nanowire approach for enhancing the quantum efficiency and the reliability in window-absorber type solar cells like CdS-CdTe, CdS-CIGS and CdS-CZTSSe.