Journal of Nanomedicine & Nanotechnology

Black diamond: A surface-nanostructured material for high temperature solar cells

11^th International Conference and Expo on Nanoscience and Molecular Nanotechnology

October 20-22, 2016 Rome, Italy

Daniele Maria Trucchi, Alessandro Bellucci, Paolo Calvani, Marco Girolami1, Stefano Orlando, Veronica Valentini and Riccardo Polini

Consiglio Nazionale delle Ricerche-Istituto di Struttura Della Materia, Italy
Università di Roma Tor Vergata, Italy

Posters & Accepted Abstracts: J Nanomed Nanotechnol

Abstract:

Black diamond is obtained by a controlled nanoscale periodic texturing of CVD diamond surface performed by means of ultrashort pulse laser. Such a process represents a technologically easy process to fabricate ripples with a periodicity of about 170 nm on diamond surface, able to drastically modify the interaction with solar radiation from typical optical transparency up to solar absorptance values even higher than 90%. Here we demonstrate that surface texturing gives rise to a strong enhancement of photo-responsivity in the visible range (up to two orders of magnitude larger than the starting transparent diamond film). The operating mechanisms of black diamond is discussed and explained by disentangling the optical enhancement from an electronic increased density of states within the diamond bandgap corresponding to an actual intermediate band able to support an efficient photoelectronic conversion of sub-bandgap photons (<5.47 eV). The introduction of an intermediate band results in an enhanced external quantum efficiency up to 800 nm wavelengths, without affecting the film transport capabilities. Here, we further discuss recent results of process development and optimization, such as a reduced periodicity of the ripples and fabrication of 2D periodic structures. The achieved optical and photoelectronic outstanding results open the path for future application of black diamond as a photon-enhanced thermionic emission cathode for solar concentrating systems, with advantages owing to the excellent electronic properties combined with a potentially very low work function and high thermal stability.

Biography :

Email: daniele.trucchi@ism.cnr.it