Hot Electron Excitation from Titanium Nitride Using Visible Light

One major strategy that has been used to inject carriers into wide-band-gap materials involves exciting hot carriers from a nano structured metal using low-energy photons. Here, we demonstrate that titanium nitride (a conductive ceramic) can be used as an alternative for photoexciting hot carriers. Planar samples that form titanium nitride/zinc oxide/titanium nitride trilayers are fabricated, and the generation of photocurrent using visible light is confirmed. The photocurrent obtained by using titanium nitride is much larger than that obtained by using gold in a similar structure. Our results will therefore facilitate the use of titanium nitride, which is robust and inexpensive, in harvesting the visible region of the solar spectrum in photovoltaics and photocatalysis.