Absorption mechanism and performance characterization of CuO nanostructured absorbers

Abstract

We introduce copper oxide (CuO) nanostructured selective solar absorbers having a broadband solar absorption over visible to near infrared wavelengths while suppressing long wavelength emission. The detailed mechanism enabling the enhanced solar absorption was investigated using the finite-difference-time-domain (FDTD) simulations. Both indoor and outdoor solar absorption experiments were conducted to investigate the performance of the suggested absorber in a well-controlled and actual operating conditions, respectively. The combined effects of the suggested absorber and double-glazing layout were also investigated. The results show that the sharp morphology of the CuO structures and its random size distribution enable the enhanced broadband optical absorption, and the resulting performance was measured to be approximately 95% and 97% of that of the current state-of-the-art TiNOX absorber for single and double glazing case, respectively. The suggested absorbers can provide a near-equivalent performance with the current-state-of-the-art solar absorber with much simpler and faster fabrication process. Furthermore, the numerical and experimental frameworks provided in this study will help develop high efficiency solar collectors.